An increasing number of men and women are being diagnosed with cancer and many cancer survivors are seeking lifestyle-based approaches to improve survival. The American Cancer Society issued nutrition and physical activity recommendations for cancer survivors in 2006. This article discusses these guidelines, including more recent publications regarding obesity, exercise, diet, and nutrient supplement use in relation to cancer outcomes including survival. Observational data strongly indicate that obesity, weight gain, and physical inactivity are adverse prognostic factors, although data on diet or supplement use in relation to cancer survival are more limited and inconsistent. Randomized trials of lifestyle interventions in survivors are also very limited at present. Although there are major research gaps in the literature on nutrition and physical activity for cancer survivors, the available evidence to date suggests that physicians should be familiar with current guidelines and discuss them with their patients as an important strategy to improve long-term survival.