During menopause, women undergo a series of physiological changes that include a redistribution of fat tissue. This study was designed to investigate the effect of adding 10 g of cocoa-rich chocolate to the habitual diet of postmenopausal women daily on body composition. We conducted a 6-month, two-arm randomised, controlled trial. Postmenopausal women (57·2 (sd 3·6) years, n 132) were recruited in primary care clinics. Participants in the control group (CG) did not receive any intervention. Those of the intervention group (IG) received 10 g daily of 99 % cocoa chocolate in addition to their habitual diet for 6 months. This quantity comprises 247 kJ (59 kcal) and 65·4 mg of polyphenols. The primary outcomes were the between-group differences in body composition variables, measured by impendancemetry at the end of the study. The main effect of the intervention showed a favourable reduction in the IG with respect to the CG in body fat mass (–0·63 kg (95 % CI –1·15, –0·11), P = 0·019; Cohen’s d = –0·450) and body fat percentage (–0·79 % (95 % CI –1·31, –0·26), P = 0·004; Cohen’s d = –0·539). A non-significant decrease was also observed in BMI (–0·20 kg/m2 (95 % CI –0·44, 0·03), P = 0·092; Cohen’s d = –0·345). Both the body fat mass and the body fat percentage showed a decrease in the IG for the three body segments analysed (trunk, arms and legs). Daily addition of 10 g of cocoa-rich chocolate to the habitual diet of postmenopausal women reduces their body fat mass and body fat percentage without modifying their weight.