BACKGROUND: Clinic no shows (NS) create a lost opportunity for provider-patient interaction and impose a financial burden to the healthcare system and on society. We aimed to: (1) to determine the clinical and demographic factors associated with increased NS rates at a children's hospital's subsubspecialty clinics and (2) to estimate the direct institutional financial costs associated with NS events. METHODS: A comprehensive database was generated from all clinic encounters for 15 subspecialty outpatient clinics (five surgical and 10 medical) between September 12, 2005 and December 30, 2010. Multivariate logistic regressions were performed to identify the variables associated with NS events. Direct costs of NS events were estimated using annual revenue for each clinic. RESULTS: A total of 284,275 encounters and 17,024 NS events were available for analysis. Public insurance coverage (Medicaid and Title V), compared to private insurance or self-pay status, was associated with an increased likelihood NS (OR 2.19, 95% CI 2.10-2.28, p < 0.0005 for Medicaid; OR 1.56, 95% CI 1.50-1.62, p < 0.0005 for Title V). Compared to patients 21-30 years of age, patients <12 years (OR 2.08, 95% CI 1.77-2.45, p < 0.0005) had increased likelihood of NS. Scheduled visits with medical subspecialists were more likely than surgical subspecialty visits to result in a NS (OR 1.69, 95% CI 1.63-1.75, p < 0.0005). The predicted annualized lost revenue associated with NS visits was estimated at $730,000 from the 15 clinics analyzed, approximately $210 per NS event. CONCLUSION: Pediatric subspecialty NS events are common, costly, and potentially preventable.