Many studies have addressed sex differences in patients with psoriatic arthritis, although these are aimed more at describing the phenotype than at investigating the causes underlying the differences. Cross-sectional study of 203 patients. The clinical and demographic variables included age, years of education, time since onset, smoking, type of treatment, clinical presentation, number of entheses affected, dactylitis, fatigue, and cutaneous involvement. Disease activity,functioning and disease was measured. The comorbid conditions evaluated included obesity (and leptin as an associated parameter), anxiety and depression, and sleep quality. Mean age was 54.6, and 46.8% of patients were women. Women less frequently presented axial involvement and more frequently presented enthesitis. They also presented greater disease activity, greater disease impact, and poorer functioning, as well as greater fatigue. As for comorbid conditions, women presented a higher leptin/BMI ratio, higher levels of anxiety and depression, and poorer sleep quality. By sex, pain affecting women was associated with the leptin/BMI ratio and sleep quality. The leptin/BMI ratio was not associated with any component of disease activity in men. Sex was associated with several clinical manifestations, disease activity, functioning, and disease impact. Leptin was associated with intensity of pain in women.