The lateral maxillary sinus augmentation (MSA) procedure has good predictability in terms of the success of bone regeneration with a low incidence of postoperative infections, estimated between 2% and 5.6%. Although the use of antibiotics is an established and standardized prophylactic measure for MSA procedures, the addition of corticosteroids still varies among clinician preference and clinical judgment. The aim of this systematic review was to identify whether the administration of corticosteroids during the MSA surgical procedure affects postoperative symptoms including swelling, pain, and infection rate. A literature search through PubMed, EMBASE, Ovid MEDLINE, and Web of Science indices, according to PICO criteria, was conducted to identify whether MSA peri-operative use of corticosteroids reduces the incidence of complications and patient morbidity. A single arm meta-analysis was performed due to the lack of randomized controlled trials (RCTs) comparing groups treated with or without peri-operative corticosteroids. The intracluster correlation co-efficient (ICC) and design effect were calculated to adjust for the clustering design. In the 37 studies included, a total of 1599 patients (378 Cort, 1221 No-Cort) were analyzed. Before and after taking account of clustering, there was statistically significant effect of corticosteroids on swelling, pain, wound dehiscence, trismus, and hematoma. The complication rates postoperatively were comparable between the two study groups, however slight differences existed in the incidence of active suppuration (1.7% [95% CI 0.7-3.9] Cort vs. 3.2% [2.2-4.5] No-Cort), wound dehiscence (3.9% [1.3-11.2] Cort vs. 2.1% [1.0-4.1] No-Cort) and trismus (2.7% [0.8-8.4] Cort vs. 1.4% [0.8-2.5] No-Cort). Although the event rate of the 1-to-2-week postoperative complications did not differ between the two groups, the lack of conclusive data and research comparing peri-operative corticosteroid use makes it impossible to draw definitive conclusions and more evidence and studies designed for this specific purpose are needed.