<p>Child sexual abuse has continued to rise in Nigeria but has remained largely underreported. This study explored the prevalence and underreporting of child sexual abuse in Nigeria and its implications on the well-being of the survivors. Twenty participants were selected for the study, using the purposive and snowball sampling techniques. Data were collected using in-depth interviews and were analyzed thematically with the use of NVivo 12. Findings revealed that fear, shame, stigma, discrimination, putting the family’s name first, taboo or abomination, poverty, threats by the perpetrators, ignorance of CSA, weak laws and lack of trust in the government, not knowing who to tell about CSA, and settlement and feelings of love were some of the causes of the prevalence and underreporting of child sexual abuse; while anxiety, depression, lack of trust, health complications, school dropout, and suicidal attempts were some of its implications on the well-being of the children. Social workers should work with relevant agencies and the government to put in place functional policies and programs that would reduce the prevalence of child sexual abuse, encourage the reporting of child sexual abuse by survivors, and reduce the implications of the practice on the well-being of the children.</p>