BACKGROUND Immediate medical assessment has been recommended for children after sexual abuse to identify physical injuries, secure forensic evidence, and provide for the safety of the child. However, it is unclear whether young children seen urgently within 72 hours of reported sexual contact would have higher frequencies of interview or examination findings as compared to those seen non-urgently or whether forensic findings would be affected by child characteristics, type of reported contact, or later events. METHODS We evaluated 190 consecutive cases of children under 13 years of age urgently referred during a 5-year period in 1998-2003 to a community child advocacy center and compared them to those non-urgently referred with regard to their physical examination findings, any sexually transmitted infections or forensic evidence, gender, pubertal development, type of contact, reported ejaculation, later bathing or changing clothes, time to examination, and gender, age and relationship of alleged perpetrator. RESULTS Children seen urgently were younger and had less frequent CPS involvement, more disclosures, and more positive physical examinations, and had more contact with older perpetrators than those seen non-urgently. Overall, most children were female and had normal or non-specific physical examinations. Certain case characteristics were predictive of evidence isolation in the 9% who had positive forensic evidence identified. Semen or sperm was identified from body swabs only from non-bathed, female children older than 10 years of age or on clothing or objects. CONCLUSIONS Female children over 10 years old who report ejaculation or genital contact without bathing have the highest likelihood of positive examinations or forensic evidence. While there are other potential benefits of early examination, physicians seeking to identify forensic evidence should consider the needs of the child and other factors when determining the timing of medical assessment after sexual abuse.