PurposeTo analyze the outcome of endoscopic sinus surgery (ESS) after preoperative systemic steroid (PSS) treatment for chronic rhinosinusitis (CRS) with nasal polyposis (NP) and to investigate and compare clinicopathological factors associated with the outcome.Materials and MethodsWe performed a retrospective chart review of 468 patients with CRS with NP who underwent primary ESS between January 2005 and October 2011. 124 patients who met the inclusion criteria were included. Beginning from 2008, our clinic administered steroid preoperatively in patients of CRS with NP, thus there were 84 patients with preoperative systemic steroid (PSS group) and another 40 patients without such regimen (no PSS group). To evaluate the outcome after ESS, poor outcome and complication were analyzed according to the following parameters: age, sex, follow-up duration, eosinophilic infiltration, atopy, asthma, Lund-Mackay score, and polyp grade.ResultsThere was no significant difference in poor outcome rates between the PSS and no PSS group (35.0% vs. 47.6%, p=0.185). There was no significant difference in complication rates between the PSS and no PSS group (10% vs. 6%, p=0.468). As with the multivariate analysis of the clincopathological factors to the poor outcome rate, presence of asthma and eosinophilic infiltration were significantly related (odds ratio as 6.555 and 4.505, respectively), whereas PSS was confirmed as less likely related (odds ratio 0.611).ConclusionLow dose PSS administration does not seem to have an effect on the outcome after ESS in patients who have CRS with NP. Eosinophilic infiltration and presence of asthma are important predictors of surgical outcome.