Children 6 months to 12 years of age with AOM were enrolled in a multi-center, single blind, comparative trial to determine the efficacy and safety of TMP oral solution. Patients were randomized to a 10 day course of TMP solution (10mg/kg/day) or TMP+SMX suspension (8mg/kg/day+40mg/kg/day) in two divided doses. Of the 262 patients enrolled in 11 sites, 226 (86%) were efficacy evaluable (TMP 115, TMP+ SMX 111). Clinical response was based on resolution of baseline signs and symptoms, otoscopic findings, relapse and recurrence rates (reappearance of signs/symptoms at day 15 or day 30, respectively). There were no significant differences in important baseline variables. A majority of patients had bilateral AOM. A satisfactory response(Complete, Partial) was observed in 90% of TMP-treated and 92% of TMP+SMX- treated patients 2-8 days post-treatment. At endpoint (≥ 25 days), clinical success response (Cure, Improvement) was observed in 71% of TMP patients and 70% of TMP+ SMX patients. Failure, Relapse and Recurrence rates were similar in both groups. Eleven (8%) patients in the TMP group and 27 (21%) patients in the TMP+SMX group reported AE's considered drug related (p=0.005); of these, skin rash occurred in 1 TMP patient and 10 TMP+ SMX patients. Study results indicate that TMP solution and TMP+SMX suspension are equally effective in AOM but that the TMP monotherapy safety profile is clinically superior.Funded by Ascent Pediatrics.