Malcolm X, along with his co-author Alex Haley, recounts the early years of his life, focusing primarily on his childhood experiences and the impact of racism on his family. Born Malcolm Little, he describes his parents, Earl and Louise Little, as proud and committed members of Marcus Garvey's Universal Negro Improvement Association (UNIA), which sought to empower Black people and promote racial pride.

Malcolm reflects on the racism his family faced in Omaha, Nebraska, and how their house was burned down by a white supremacist group, the Black Legion, when he was still a baby. The family then moved to Lansing, Michigan, where they faced continued racial harassment and violence. Tragically, Malcolm's father, Earl Little, was killed in a streetcar accident, which Malcolm believed was a murder committed by white supremacists.

After his father's death, Malcolm's mother, Louise, struggled to provide for her eight children. Her mental health deteriorated, and eventually, she was institutionalized. This left Malcolm and his siblings in the care of the state, where they were separated and placed in foster homes.

"Nightmare" sets the stage for the rest of Malcolm X's autobiography, highlighting the harsh realities of growing up Black in America in the early 20th century. The racial violence, economic hardship, and family disintegration he experienced as a child shaped his perspective on race and social justice and paved the way for his later activism.