Several studies have been conducted with the aim of investigating the effect of Omega(ω)-3 on different psoriasis indices including Psoriasis Area and Severity Index (PASI) score, erythema, scaling, itching, area involved, and infiltration. Nevertheless, a pooled analysis of trials that evaluated these variables has not been conducted. Therefore, the aim of this meta-analysis was to assess the efficacy of ω-3 fatty acids in treating patients with psoriasis. We searched through different electronic, references of retrieved articles, and previous related reviews databases up to November 2018. Both combined and stratified analyzes were conducted. A fixed-effects or random effects model was used to assess the mean effect sizes. An eventual 10 studies involving 560 participants were considered as eligible for inclusion in the present meta-analysis. The meta-analysis indicated a significant reduction in PASI score by − 1.58 (95% confidence interval (CI), − 2.24, − 0.92; P < 0.001) in favor of ω-3 polyunsaturated fatty acid (PUFA) group. The random effects model showed a statistically significant beneficial effect of ω-3 PUFA supplementation on reducing erythema by − 1.66 unit and reducing scaling (weighted mean difference (WMD), − 0.69; 95% CI, − 1.26, − 0.13; P = 0.02). Significant improvements in erythema, itching, and scale were observed in the trials which used the higher dosage of ω-3 supplementation. The results of current meta-analysis study support the use of ω-3 PUFA supplementation for the improvement of the evaluated parameters in psoriatic patients. However, well-controlled and randomized studies are needed to confirm the veracity of non-significant and/or equivocal findings.