Polycystic ovary syndrome (PCOS) is the commonest endocrine condition encountered in young women and has many reproductive, metabolic and psychological features that lead to patients consulting medical practitioners and the health service. Overweight and obesity are common among many groups of young women with PCOS and may precipitate subsequent reproductive and metabolic disorders that require expensive and invasive care. Attention to nutrition and diet is important in management of these young women. While there is little evidence from a metabolic cause for changes in appetite and fat deposition, there is a need for intervention to prevent weight gain and promote weight loss. It appears as if caloric restriction is the most important feature of treatment ahead of changes to the macronutrient component of the diet. Introduction of an active lifestyle is also encouraged. As obesity rates increase and infertility is more common, nutritional interventions have a role to play in fertility. Given the rising increase in risk in diabetes mellitus and the potential effects on cardiovascular events that will arise, health services need to approach polycystic ovarian syndrome with adequate nutritional resources for dietary intervention and advice.