Background: Induction treatment of mild-to-moderate Crohn's disease is controversial. Purpose: To compare the induction of remission between different doses of mesalamine, sulfasalazine, corticosteroids, and budesonide for active Crohn's disease. Data sources: We identified randomized controlled trials from existing Cochrane reviews and an updated literature search in Medline, EMBASE, and CENTRAL to November 2015. Study selection: We included randomized controlled trials (n = 22) in adult patients with Crohn's disease that compared budesonide, sulfasalazine, mesalamine, or corticosteroids with placebo or each other, for the induction of remission (8-17 wks). Mesalamine (above and below 2.4 g/d) and budesonide (above and below 6 mg/d) were stratified into low and high doses. Data extraction: Our primary outcome was remission, defined as a Crohn's Disease Activity Index score <150. A Bayesian random-effects network meta-analysis was performed on the proportion in remission. Data synthesis: Corticosteroids (odds ratio [OR] = 3.80; 95% credible interval [CrI]: 2.48-5.66), high-dose budesonide (OR = 2.96; 95% CrI: 2.06-4.30), and high-dose mesalamine (OR = 2.29; 95% CrI: 1.58-3.33) were superior to placebo. Corticosteroids were similar to high-dose budesonide (OR = 1.21; 95% CrI: 0.84-1.76), but more effective than high-dose mesalamine (OR = 1.83; 95% CrI: 1.16-2.88). Sulfasalazine was not significantly superior to any therapy including placebo. Limitations: Randomized controlled trials that use a strict definition of induction of remission and disease severity at enrollment to assess effectiveness in treating mild-to-moderate Crohn's disease are limited. Conclusions: Corticosteroids and high-dose budesonide were effective treatments for inducing remission in mild-to-moderate Crohn's disease. Highdose mesalamine is an option among patients preferring to avoid steroids.