Background: Psoriatic arthritis (PsA) is distinguished by spondylitis, dactylitis, peripheral arthritis, and skin psoriasis. Dickkopf-1 (DKK-1) is thought to be the primary suppressor of the Wnt signaling pathway, resulting in decreased osteoblast proliferation. Objective: This study determined DKK-1 serum levels and its relationship with disease severity and activity in PsA patients.        Patients and Methods: Enzyme-linked immunosorbent assay (ELISA) was used to measure serum DKK-1 levels in 45 patients with PsA and 45 healthy age and gender harmonized people as a control group. All patients were recruited from the Rheumatology, Rehabilitation, and Physical Medicine Outpatient Clinic and Inpatient Department at Benha University Hospitals. PsA Disease Activity Score (PASDAS) was utilized to assess disease activity, while Simplified Psoriatic Arthritis Radiographic Score (SPARS) and PsA Impact of Disease (PsAID) were used to assess disease severity. Results: The mean serum DKK-1 levels in PsA patients was significantly higher than in control group [p < 0.001]. In addition, it increased gradually in remission, low, moderate then high activity cases (p < 0.001). As regards disease severity, unacceptable status showed significantly higher DKK-1 level when compared to acceptable status. Also, a statistically significant correlations between serum levels of DKK-1 and PASDAS, PsAID, and SPARS was discovered. Conclusion: DKK-1 serum levels were abnormally high in PsA patients. Elevated DKK-1 levels had a significant role in the process of structural radiographic alterations, as well as disease severity and activity in PsA patients.