Background: The risks of breast and ovarian cancer associated with BRCA1 and BRCA2 mutations are well established. Investigations of the association of BRCA mutations and the risk of colorectal cancer(CRC) have yielded conflicting results. We performed a systematic review of published and unpublished studies evaluating BRCA and CRC risk, and meta-analyses to quantify overall CRC risk and in subgroups of BRCA mutation carriers. Methods: Eligible studies were retrieved from PubMed/MEDLINE, Embase, Cochrane, Scopus, and ProQuest Dissertation & Theses. Unadjusted odds ratios were used to derive pooled estimates of CRC risk overall (combined BRCA1/BRCA2) and in subgroups defined by mutation type, comparison group, and study design. Both fixed and random effects models were estimated with the latter having priority. We followed the guidelines summarized in the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) as well as the Meta-analysis of Observational Studies in Epidemiology (MOOSE) statements. Results: A total of 18 studies were included in the systematic review: 7 cohort studies comparing to the general population, 5 case-control studies, 4 cohort studies involving pedigree analysis, and 2 kin-cohort studies. Fourteen studies included in the systematic review were used in the meta-analysis. The overall BRCA1/BRCA2 meta-analysis revealed an increased CRC risk in a fixed-effects (OR = 1.22, 95%CI = 1.01-1.48, p = 0.041, I²= 19.5%) but not in a random-effects model (OR = 1.20, 95%CI = 0.96-1.50, p = 0.111). In subgroup random-effects meta-analyses, BRCA1 was associated with increased CRC risk (OR = 1.48, 95%CI = 1.13-1.94, p = 0.005, I²= 3.7%) but BRCA2 was not. Analyses stratified by study design and comparator found no association between BRCA mutation and CRC risk (all 95%CIs crossing 1, all p > 0.05). Conclusions: Although studies differed in their findings about the association between BRCA mutations and CRC risk, meta-analyses revealed a potential 1.22-fold greater risk of CRC in BRCA mutation carriers. This elevated CRC risk was attributable largely to a 1.48-fold greater risk in BRCA1 mutation but not in BRCA2 carriers, regardless of age.