Background Biological drugs for moderate-to-severe ulcerative colitis have changed the therapeutic perspective, while small-molecule inhibitors and new promising drugs suggest new options. Aim Assess comparative efficacy and safety of biological and new small oral drugs: commercialized and under-investigation ones for patients naïve to biological drugs. Methods A systematic review was conducted to identify the randomized clinical trials phase 2 or 3, in adults with moderate-to-severe ulcerative colitis treated with biological drugs (infliximab, adalimumab, golimumab, vedolizumab and etrolizumab) or new oral small molecules (tofacitinib and ozanimod) as first line. A Bayesian network metaanalysis was performed to inform comparative efficacy and safety of different treatments. Efficacy outcomes were clinical remission, clinical response and mucosal healing for induction therapy and clinical remission, mucosal healing and sustained clinical remission for maintenance therapy. Safety was assessed with serious adverse events and rates of infections. Results 14 references were included for network meta-analysis. For induction therapy, infliximab was the best drug for induction of clinical response and remission, while ozanimod showed to be the best for induction of mucosal healing. Tofacitinib had the highest rate of maintaining clinical remission. All treatments were similar for serious adverse events, and vedolizumab and tofacitinib had the highest rates of infections. Conclusion This network meta-analysis suggests infliximab may be the best therapeutic option for moderate-to-severe ulcerative colitis. Vedolizumab seems to have better outcomes in maintenance than in induction therapy and it appears superior to golimumab and adalimumab. Tofacitinib, ozanimod and etrolizumab show encouraging results.