Aim The aim of this systematic review and meta-analysis was to analyse the clinical performance of GIOMER restorative composites and compare them with other conventional restorative materials in permanent teeth.Methods Searches in PubMed, Web of Science, Scopus, Ovid and Cochrane Library were conducted. Grey literature search was also performed. Clinical trials that evaluated the clinical performance of restorations with GIOMER restorative composites in permanent teeth compared to those using composite resin, glass ionomer cement, resin-modified glass ionomer cement (RMGIC) and other GIOMERs were included. Meta-analyses comparing GIOMER restorative composites with RMGIC at 6- and 12-month follow-ups and comparing two types of GIOMER were feasible.Results Ten studies fulfilled the inclusion criteria. In these studies, GIOMER was compared to different types of dental restoration materials. Dental restorations were evaluated by United States Public Health Service criteria in all included studies. Four studies were suitable for meta-analysis, which showed significant differences between GIOMER and RMGIC surface roughness at 6-month (odds ratio [OR] = 6.56; 95% confidence interval [CI] = 2.38-18.13) and 12-month (OR = 8.76; CI = 3.19-24.07) follow-ups. No significant differences between GIOMER restorative composites and RMGIC for marginal adaptation were found at 6- and 12-month follow-ups. When comparing two GIOMERs, significant differences were seen between Beautifil II and Beautifil Flowable Plus F00 for marginal staining (OR = 2.58; CI = 1.42-23.27; I2 = 0%) and surface roughness (OR = 4.59; CI = 1.11-18.97; I2 = 0%) at the 36-month follow-up. No significant differences between Beautifil II and Beautifil Flowable Plus F00 were seen for marginal adaptation and anatomic form at 6-, 18- and 36-month follow-ups.Conclusions GIOMER restorative composites presented similar performance concerning marginal adaptation and better surface roughness when compared to RMGIC. GIOMER Beautifil II presented similar performance to GIOMER Beautifil Flow Plus F00 concerning marginal adaptation and anatomic form and worse marginal staining and surface roughness when compared to Beautifil Flowable Plus F00.