Background: Patients (pts) with aggressive lymphoma are generally treated with curative intent and many become long-term survivors. There is little data on health behaviors after lymphoma diagnosis and their effect on QOL and long-term outcomes. Methods: Lymphoma pts were prospectively enrolled within 9 months of diagnosis in the University of Iowa/Mayo Clinic SPORE Molecular Epidemiology Resource (MER) and systematically followed. We measured QOL (FACT-G) and health behaviors (tobacco/alcohol use; diet/exercise habits) 3 years after diagnosis. For this study, “survivor” was defined as alive at 3 years from diagnosis with no active disease or treatment within the previous year. Results: From 2002-2012, 671 patients with aggressive lymphoma were enrolled, met survivor definition, and completed 3-year QOL and health behavior questionnaires. At 3-years, 31% of female (F) and 48% of male (M) reported a history of tobacco use for 6+ months. Of these, 13% of F and 7% of M were still smoking; 52% reported decreased use from baseline. 66% reported no change in alcohol intake at 3-years while 25% of F and 34% of M reported decreased intake. 60% often chose whole grains and 65% get 2+ servings of vegetables daily. 42% of F and 38% of M “somewhat” believed diet could change the course of their lymphoma. Most pts endorsed no significant change in diet as a result of diagnosis. Those who made changes did so primarily out of concern for “health problems other than cancer”. Overweight/obese responders were 72% pre- and 66% post-treatment. A desire to lose weight was reported by 55% of pts. 14% of F and 23% of M often engaged in regular physical activity (PA). Nearly 50% reported a decrease in PA. Pts with advanced stage (p = 0.006), age > 60 (p = 0.001), ECOG PS > 2 (p = 0.04), and worse prognostic score (p = 0.006) were more likely to report decreased PA since diagnosis. 68% of F and 61% of M intend to become more active in the next months. Regular PA (p = < 0.0001) was associated with higher QOL, while increased alcohol intake was associated with lower QOL (p = 0.009) at 3 years. Conclusions: Many survivors of aggressive NHL strive to adopt healthy behaviors and these behaviors are associated with higher QOL. Interventions aimed at emphasizing these behaviors may have potential to improve long-term outcomes and QOL.