As the link between maternal obesity and risk of autism among offspring is unclear, the present study assessed this association. A systematic search of an electronic database was performed to identify observational studies that examined the association between maternal obesity and autism. The outcome measures were odds ratios comparing offspring autism risk between obese and normal-weight mothers. Five observational studies were included in the meta-analysis. A fixed-effects model was used since low heterogeneity was observed between studies. The pooled adjusted odds ratio was 1.47 (95 % CI 1.24–1.74). The meta-analysis results support an increased risk of autism spectrum disorder in children of women who were obese during pregnancy. However, further study is warranted to confirm these results.