Objective: In current standard practice the therapeutic pressure of CPAP is determined by manually titration under attended polysomnography (PSG). Since PSG is not easily accessible, auto-CPAP may be an attractive alternative. Our goal is to compare the pressure levels obtained from home auto-CPAP with overnight PSG titration in children with OSA. Methods: We performed a prospective cohort study in 2-18 year-old children with OSA referred for CPAP titration under PSG. Children were instructed to use auto-CPAP devices at home for 8 weeks, either before or after PSG titration. One night PSG titration was performed following AASM clinical guidelines for the manual titration of positive airway pressure. Data from only those children who used auto-CPAP ≥ 4 hours per day, for >consecutive 7 days and percent days with device usage ≥ 80% were selected for analysis. Average device pressure ≤ 90% of time from auto-CPAP were obtained and compared with PSG titrating pressure. Results: Eleven of 17 children were enrolled and completed the protocol (male 9/11, aged 9.6 ± 4.2 years, BMI 31.5 ± 10.0 kg/m 2). Three children refused to use auto-CPAP. Three children were non-adherence. Six of 11 children had already undergone adenotonsillectomy. There were no significant differences in the pressure levels obtained from home auto-CPAP and PSG titration (11.05 ± 3.68 vs. 11.18 ± 3.34 cm H 2 O, p=0.84). However, when considering on actual values of the pressure, only 5/11 children had pressure differences <2 cm H 2 O. Pressure levels obtained from auto-CPAP significantly differed from PSG titration in the group of children with history of adenotonsillectomy (p=0.036). Conclusion: In children with OSA, the use of home auto-CPAP may not accurately determine the therapeutic CPAP pressure as compared with manually titration under attended PSG, especially in children who previously had adenotonsillectomy.