The data search was conducted into three main databases: PubMed, Embase, and Cochrane. The search equation was built around the PICO framework in which the population was constituted by human adults suffering from chronic periodontitis that had to be treated with conventional SRP with the adjunction of omega-3 fatty acids (I) or without the adjunction of omega-3 fatty acids (C), with, as a first outcome the probing pocket depth reduction (PPD) and as a second outcome the clinical attachment loss reduction (CAL). Risk of bias within studies was evaluated for each included study using the Cochrane collaboration tool for randomized studies (RoB Tool). A meta-analysis was performed using REVMAN 5.3. After a global search, 117 studies were selected but only seven of them were eligible for the systematic review and meta-analysis. Six out of seven studies showed a significantly better PPD reduction in the omega-3 fatty acids group compared to the control group and five out of seven studies showed a significantly better CAL reduction in the omega-3 fatty acids group compared to the control group. The meta-analysis showed a statistically significant difference for PPD reduction (SMD: -0.78 [95% CI: -1.02, -0.54, p < .0001]) and CAL reduction (SMD:-0.80 [95% CI: -1.04, -0.56, p < .0001]) in favor of the test group. After scaling and root planning, PPD reduction and CAL reduction were observed in both control and test groups, but with statistically significant better values for the omega-3 fatty acids group. Patients suffering from periodontitis could benefit from the use of omega-3 fatty acids to increase the effectiveness of a nonsurgical treatment.