This study hypothesises that an educational leaflet about psoriatic arthritis (PsA) will improve psoriasis patients' attendance for screening for PsA. A random sample of patients 18 years old with a coded diagnosis of psoriasis and no diagnosis of PsA, rheumatoid arthritis or ankylosing spondylitis were identified from five GP surgeries in Yorkshire, UK. Patients were randomised 1:1 to receive study information alone or with the educational leaflet, with an invitation to attend for a screening examination by a dermatologist and rheumatologist. Nine hundred thirty-two invitation packs were sent to recruit 191 (20.5%) participants. One hundred sixty-nine (88.5%) had current or previous psoriasis and 17 (10.1%) had previously undiagnosed PsA. The estimated prevalence of PsA was 18.1% (95% CI: 16.2, 20.1%). The response rate was lower than expected and was not significantly higher when patients received the educational leaflet (22.8 vs 18.3%, p = 0.08). Response rates varied by practice (14.7 to 30.6%). However, deprivation scores for each practice revealed a significant increase in response with the leaflet for deprivation decile of 3 (p < 0.001) but no significant differences in the other practices. An educational leaflet about PsA improves attendance for screening in primary care, but only in those practices with higher levels of socioeconomic deprivation.