Background: We summarize utilization patterns for mental health services in school-based health centers. Methods: Administrative data on school-based health center visits in New Haven, Connecticut were examined for the 2007-2009 school years. Relative frequencies of mental health visits by age were calculated as a percentage of all visits and were stratified by sex, ethnicity/race, and insurance status. Results: Mental health visits accounted for the highest proportion of visits (31.8%). The proportion of mental health visits was highest at 8 years (42.8%) and at 13 years (39.0%). The proportion of mental health visits among boys (38.4%) was higher than among girls (26.7%). Hispanic students had a lower proportion of mental health visits than black students (23.5% vs 35.8%) in all but 2 age groups. Students in the white/other ethnicity category had higher proportions of mental health visits than Hispanic and black students between ages 12 and 15. Students with no health insurance (22.5%) had lower proportions of mental health visits than students covered by Medicaid (34.3%) or private insurance (33.9%). The percentage of mental health visits by students with private insurance was highest (37.2%-49%) in the 13-15 age range. Conclusions: Usage patterns for mental health issues show pronounced, nonrandom variation relative to age and other demographic characteristics especially with 8-year-old boys.