Lifestyle intervention is first line treatment in obese women with polycystic ovary syndrome (PCOS). The effect of motivational interviewing (MI) as add on to standard advice (SA) on weight loss and quality of life (QoL) has not been evaluated in obese women with PCOS. We aimed to examine whether MI as add on to SA induced higher weight loss and improved QoL in obese women with PCOS. Thirty-seven obese women with PCOS (BMI ≥30 kg/m2) were randomized to MI + SA (n = 19) vs. SA (n = 18) for six months. Anthropometric measures (BMI, waist) and questionnaires (World Health Organization-5 (WHO-5), Major Depression Index (MDI), Short Form-36 (SF-36) and PCOS-Questionnaire (PCOS-Q)) were performed at baseline and at follow-up, www.clinicaltrials.gov, NCT02924025. Twenty-eight (14 + 14) women completed the study. At baseline, 24/28 women had WHO-5 scores <67 and 12/28 women had MDI scores indicating depression. Changes in weight and QoL were similar between MI + SA vs. SA group. However, WHO-5 (p=.028) and MDI (p=.008) scores improved significantly in the 12/24 women with MDI scores indicating depression. MI as add on to SA did not improve QoL or weight loss. Obese women with PCOS had low QoL.