So far, a recognizable pattern of clinical symptoms for child sexual abuse (CSA), especially in young male children, is lacking. To improve early recognition of CSA, we reviewed physical complaints, physical examination, and tests on sexually transmitted infections (STIs) in confirmed victims (predominantly preschool boys) of CSA from the Amsterdam sexual abuse case (ASAC). We retrospectively analyzed the outcomes of the primary assessment using mixed methods: descriptive analysis of physical complaints, physical exams, and STI tests from medical files and a qualitative analysis on expert’s interpretations of physical complaints and children’s behavior during physical examination. We included 54 confirmed CSA victims, median age 3.2 (0-6) years, 43 boys (80%), and 11 girls (20%). Physical complaints were reported in 50%, of which gastrointestinal and anogenital complaints were most common. None of the children showed CSA-specific genital signs at physical examination. Most prominent finding during physical examination was a deviant behavioral response (anxiety, withdrawal, too outgoing) in 15 children (28%), especially in children who experienced anal/vaginal penetration. Testing for STIs was negative. Conclusion: Physical complaints and physical signs at examinations were non-specific for CSA. Deviant behavioral reactions during physical examination were the most prominent finding. Precise observation of a child’s behavior during physical examination is needed.