OBJECTIVE The aim of this study was to evaluate the response to weight loss guidance in the anthropometric parameters of obesity and overweight infertile patients assisted fertilization treatment (high and low complexity). METHODS Retrospective cohort study. This survey was conducted in a population of overweight and obese infertile patients. In the first consultation at the assisted reproduction clinic (Human Reproduction Laboratory HC / UFG), obese and overweight patients were weighed, measured and instructed to lose weight and informed that being overweight could reduce the chances of success in the treatment. RESULTS We analyzed 56 overweight and obese patients admitted for infertility treatment at the Human Reproduction Center HC/UFG. The mean age of overweight and obese patients was 35.78 years, SD 3.70. After the orientation, only 8.92% of patients would achieve the normality rating for BMI, overweight 39.28% (decreased 14.29%), obesity I 37.5%, obesity II 10.71% and obesity III 3.57% (all degrees of obesity increased 1.79%). The mean weight of patients before and after guidance was statistically significant (p<0.0046). The mean values of BMI before and after guidance were also statistically significant (p<0.0038). CONCLUSIONS Weight loss guidance in this population had no effect on weight loss. On the contrary, the mean weight of patients after guidance was statistically higher than the mean in the first consultation (both weight and BMI). It is suggested that for obese and overweight infertile patients, in addition to guidance for reduction, an appointment with a nutritionist and/or endocrinologist should be immediately scheduled.