The novel opens in Lagos in 1934 with the cinematic image of Nnu Ego running wildly through the streets after discovering the body of her dead baby.  She is sightless, wordless, and formless. With no identity outside the designation of mother, she feels she is incapable of existing.  A fellow Igbo who encounters the despairing woman prevents her suicide and, from this point, Nnu Ego's journey through life unfolds before her like the life of a person who is about to drown. The narrator's reference to drowning warns the reader that the story we are about to experience is the story of a person who will not survive. Nnu Ego's failure to conceive in the first months of marriage seriously affects the rest of her life. She becomes emotionally unstable and is beaten and finally rejected by her husband. She is returned to her father, who by custom is obliged to find her another husband. She is required to travel to Lagos, far from her tribal connections, to live with her new husband Nnaife, a man whom she finds repellent.

    Nnu Ego's reaction to Nnaife (translated from Igbo means "Little Father", another of the novel's many paradoxes) indicates her own ideas about what constitutes masculinity. She says that "with a belly like a pregnant cow" (42), and his hair worn in the long style of a mourning widow, Nnaife has the appearance and demeanour of a middle-aged woman. To Nnu Ego and the society in which she lives, a middle-aged widow has, of course, no value. She is husband-less and past her childbearing years. Through Nnu Ego's harsh appraisal, the reader learns that the colonisation by, and servitude to, the British has not just emasculated Igbo men like Nnaife, but also made them worthless. In a society in which domestic servitude is equated with femininity, their loss of power is confirmed by their feminine appearance. Nnu Ego also notes with some irony that the economic exploitation of men like Nnaife is tantamount to slavery, which colonial rule has nevertheless deemed immoral and has made illegal for indigenous Nigerians to practice.
 

    Throughout the text, as in Emecheta's other work, marriage and motherhood are constructed as modern allegories for slavery.  In The Joys of Motherhood, Nnu Ego works extremely hard for very little money to feed and educate her children. In addition, the unexpected and enduring love she has for her children becomes itself a form of emotional bondage from which escape is impossible. The narrative makes a series of connections between marriage, motherhood, slavery, and colonisation: all form a unique literary discourse that has the potential to be shared by other women writers of the Black Diaspora.  A literature that acknowledges a common history of slavery and colonisation, overlaid with contemporary representations of marriage and motherhood, is capable of uniting the political concerns of Black women in different parts of the world, and also of stressing the importance of the individual in the face of change.

    Throughout the text, we are frequently reminded of Nnu Ego's chi, a spirit who accompanies her throughout her life and who is responsible for both her good and bad fortune. Nnu Ego's chi is the spirit of a slave woman who was buried alive with her dead mistress, the senior wife of Nnu Ego's father. With the difficult circumstances that befall Nnu Ego in adulthood—infertility, poverty, hunger, and exploitation—the chi appears to impose upon the living woman her own lowly rank, and what Nnu Ego perceives as the slave's revenge provides her with an explanation for her misfortune.

    Nnu Ego is overjoyed when she discovers she is capable of conceiving after all and she is able to enjoy, for a brief period pregnancy and motherhood unimpeded by tradition in which motherhood is constructed as a duty to the father and husband. Her new-found ability to bear children does not only satisfy her maternal longings and fulfil social expectations, it provides her with the only form of feminine identity she is permitted, or can contemplate: motherhood. After her son's birth, she feels like a "real woman" and is gratified that there will be somebody left behind to refer to her as "mother" (54). Thus Nnu Ego's overriding desire to be a mother is important for her in death as well as in life. Immediately after her first child dies in infancy, Nnu Ego publicly attempts suicide by trying to fall from a busy bridge.  A bystander comments that she is not mad but that, "she has only just lost the baby that told the world that she was not barren" (62). Later in the novel, in a contest between mother and father for control over the oldest son, Nnaife's younger wife tells Nnu Ego that, "In Ibuza sons help their father more than they ever help their mother.  A mother's joy is only in the name" (122). Here, Adaku reminds Nnu Ego that the joy of motherhood is only ever an illusion; that mothers cannot expect to gain happiness from the children themselves, only a kind of happiness gained from the knowledge of the status that motherhood brings. Adaku here expresses the wisdom that continues to elude Nnu Ego and, for a period in the narrative, she represents the voice of modern Black feminism.

    Despite her conservatism, Nnu Ego is nevertheless consistently critical of the institution of marriage, especially for women displaced in the city, but she is unwilling to consider the alternatives.  Respectability prevents her from becoming a prostitute and custom and pride preclude her from returning her father's village; Nnu Ego must therefore brace herself for a life of poverty and sacrifice. She recognises that she must endeavour to engage in trade in order to supplement her husband's meagre income, but living away from family support makes this very difficult, if not impossible. The narrative is equally critical of European bourgeois marriages like that of Nnaife's employers, Dr and Mrs Meers. Nnu Ego is outspoken about the unfair position of Nigerian women in marriage, but she is also disgusted by the idle Mrs Meers, who while berating her contemptuous husband, nevertheless submits eagerly to economic dependence on him.