Background This study was planned to evaluate the strength, proprioception, skill, coordination, and functional condition of the hand in individuals with psoriatic arthritis and to correlate disease activity with these parameters. Methods Fifty-six individuals (psoriatic arthritis group, n = 36; control group, n = 20) were included in the study. Evaluations were performed of disease activity with Disease Activity Score 28; grip strength with a dynamometer and pinch strength with pinch gauge dynamometers; joint position sensation with a goniometer; finger skills with a mobile application; and coordination and skill of both hands with the Purdue Pegboard test. The Michigan Hand Outcomes Questionnaire (MHQ) was used for hand functional evaluation. Results There was a significant difference between the grip and pinch strength of the psoriatic arthritis group and the control group (P < 0.05). There was no significant difference between the joint position sense measurements and the mobile application scores between the groups (P > 0.05). Purdue Pegboard scores showed a significant difference only in both hands and assembly subsections (P < 0.05). With Disease Activity Score 28, significant correlations were found between grip and pinch strength, mobile application scores, Purdue Pegboard all subsections, and left-hand joint position sense average error amount, and between MHQ and grip and pinch strength. Conclusions This study is the first to show that psoriatic arthritis has a negative effect especially on hand strength; grip strength decreases as disease severity increases and, skill, coordination, and functionality of hand deteriorate.