Introduction <p>Psoriasis is a chronic inflammatory skin disorder affecting millions worldwide. Dermoscopy and proximal nailfold capillaroscopy have emerged as valuable tools for understanding the pathophysiology and treatment response of psoriasis lesions.</p> Objectives <p>This study aimed to contribute to the limited literature on using dermoscopic findings to detect treatment effectiveness in patients with psoriasis vulgaris.</p> Methods <p>This prospective, single-blinded, observational cohort study included 101 patients aged 18–71 years diagnosed with psoriasis vulgaris who initiated or altered systemic treatment. Monthly dermoscopic and capillaroscopic evaluations were performed alongside assessments of Psoriasis Area Severity Index (PASI), Body Surface Area (BSA), and Dermatology Life Quality Index (DLQI) scores.</p> Results <p>A significant relationship was found between first-month dermoscopic findings and third-month severity scores (PASI, BSA, DLQI). Patients with positive treatment responses exhibited changes from baseline regular capillary dilations to hemorrhagic spots or the absence of vascular findings during the first month. The correlations between dermoscopic changes and severity scores evolved over time, becoming stronger in the second and third months. Nailfold capillaroscopy findings at the third month of treatment showed significant differences from baseline.</p> Conclusions <p>Dermoscopy is a fast, practical, and inexpensive tool for early prediction of treatment effectiveness in psoriasis vulgaris. The disappearance of regular capillary dilations or their change to hemorrhagic spots suggests treatment efficacy, while their persistence indicates poor treatment response. Early detection of treatment effectiveness using dermoscopic findings can facilitate timely adjustments, improving patient outcomes and reducing unnecessary treatment exposure.</p>