Introduction Colorectal cancer is a disease influenced by genetic and environmental factors. Medicinal fungi and/or its extracts have been used in the adjuvant therapy of cancer because of their pharmacological, nutritional and immunomodulatory properties. Objective To evaluate the anthropometric profile of colorectal cancer women after dietary supplementation with Agaricus sylvaticus fungus. Methods Randomized, double-blind, placebo-controlled clinical trial was conducted in a public hospital in the Federal District – Brazil for six months. Sample of 32 patients with colorectal cancer, female, was separated into two groups: supplemented with Agaricus sylvaticus (30 mg/kg/day) and placebo. We conducted anthropometry (weight, height, body mass index, arm circumference, triceps skinfold, arm muscle circumference and fat percentage) during the treatment. The results were analyzed at three different times (before the start of treatment, three months and after six months supplementation) using the Microsoft Excel 2007 and SPSS 19.0, using Student's t-test and F, with significance for p ≤ 0.05. Results The Agaricus sylvaticus group showed a significant increase in body mass index, arm circumference, percent body fat and triceps skinfold, and non-significant increase in arm muscle circumference after six months of supplementation. These results were not observed in the placebo group. Conclusion The results suggest that dietary supplementation with Agaricus sylvaticus is capable to have benefits in anthropometric parameters of women with colorectal cancer.