Objectives This study aims to examine the prevalence of comorbidities in adult patients with psoriasis and compare them with those in control subjects without psoriasis in Tianjin, China.Design The study is a cross-sectionalanalysis.Participants The participants were established by identifying all patients (age ≥18 years) who visited hospitals and clinics in Tianjin between 1 January 2016 and 31 October 2019.Setting The study group consisted of 20 678 adult patients with psoriasis, and a comparison group was created after 1:1 propensity score matching. Logistic regression analyses were conducted to examine the risk of 22 comorbidities for these two groups.Results Patients with psoriasis had a significantly higher prevalence of 11 comorbidities and a lower prevalence of 2 comorbidities within 12 months of follow-up. Our results also showed that the proportion of psoriatic arthritis might account for approximately 2% of all patients with psoriasis. This psoriatic arthritis group had a higher average age and CCI (Charlson Comorbidity Index) index score (2.27 >1.62, p <0.001) than the non-arthritis group.Conclusions This study showed that psoriasis in Tianjin is associated with various comorbidities. It also emphasises the importance of clinical treatment in improving therapeutic effects and reducing the burden of psoriasis in China.