Many studies have reported that exposure to ambient air pollution has adverse effects on health. However, there are little researches to explore the relationship between ambient air pollution and chronic sinusitis (CS). From January 1 2015 to December 31 2018, a time-series study were carried out to investigate the acute adverse roles of six criteria ambient air pollutants (fine particulate matter [PM_2.5], inhalable particulate matter [PM₁₀], nitrogen dioxide [NO₂], sulfur dioxide [SO₂], ozone [O₃], and carbon monoxide [CO]) in hospital outpatients with CS in Xinxiang, China. Then, an over-dispersed Poisson generalized additive model was utilized to analyzed the relationships. In total, 183,943 hospital outpatient cases of CS were identified during the study period. We found that a 10 μg/m³ increase in PM_2.5, PM₁₀, SO₂, NO₂, and CO corresponded to 0.48% (95% confidence interval: 0.22–0.74%), 0.33% (0.16–0.50%), 0.88% (0.13–1.62%), 1.98% (1.31–2.64%), and 0.05% (0.03–0.07%) increments, respectively, in CS outpatients on the current day. The young group (<15 years of age) was more susceptible than the adult or elderly groups. These results suggested that outdoor air pollutants might increase CS outpatient, especially among youth in Xinxiang. Precautions and protective measures should be strengthened to reduce the air pollution level in the future.