Type 1 and type 2 diabetes are among the most prevalent chronic diseases in women in the fertile years and women with diabetes may experience several reproductive issues. We aimed to examine the chance of biochemical pregnancy, clinical pregnancy and live birth after assisted reproductive technology (ART) treatment in women with type 1 and type 2 diabetes and whether obesity per se influenced the results.This nationwide register-based cohort study is based on the Danish ART Registry comprising 594 women with either type 1 diabetes or type 2 diabetes from 2006 to 2017.Relative to women without diabetes, the adjusted OR (95% CI) of a live birth per embryo transfer was 0.50 (0.36, 0.71) in women with type 2 diabetes and 1.10 (0.86, 1.41) in women with type 1 diabetes.Our data on the efficacy of ART treatment in women with type 1 and type 2 diabetes is the first in this field. When compared with women without diabetes, women with type 1 diabetes had an equivalent chance of a live birth per embryo transfer whereas women with type 2 diabetes had a reduced chance. The findings in women with type 2 diabetes did not seem to be driven by obesity per se as the same pattern was seen in both normal-weight and obese women. Graphical abstract.