During the last decade, much attention has been paid to the risk factors of sudden infant death syndrome (SIDS). Many researchers have demonstrated that infant-care practices are linked to the risk of SIDS. Prone sleeping, bed sharing, maternal substance abuse, and cigarette smoking have been reported to be significant potentially modifiable risk factors for SIDS. Despite the reports that the incidence of SIDS has decreased by 38% in the United States, it remains the leading cause of death in the first year of life. Deaths resulting from child abuse or neglect inflicted or permitted by their caretakers being second only to SIDS in infant mortalities and some recommendations regarding the differentiation of SIDS and child abuse have generated speculation that some cases of infanticide were misdiagnosed as SIDS. To reach a proper conclusion as to the cause and manner of death of an infant who died suddenly and unexpectedly, investigation must be thorough and professional.