Background This study aimed to examine whether fear of cancer recurrence (FCR) was related to two important health behaviours (physical activity and smoking) in a large sample of colorectal cancer patients. Methods Ten thousand nine hundred sixty nine patients, diagnosed in 2010–11, and in remission in 2013, completed the ‘Living with and Beyond Colorectal Cancer’ survey. The survey included purpose‐designed questions on fear of recurrence (‘I have fear about my cancer coming back’), demographics, treatment and health variables. Physical activity (PA) was recorded as number of days per week doing at least 30 min of brisk activity, and smoking status was reported. Results Fifty per cent of respondents reported fear of their cancer returning. More women than men ((Odds Ratio; (OR) 1.58; 95% confidence interval (CI) 1.46, 1.71)) more younger than older patients (OR 2.53; CI 2.33, 2.74) and slightly more patients from deprived areas (OR 1.14, 1.05, 1.23) reported FCR. Independently of demographics and treatment, compared with those meeting the PA guidelines, those who were doing only ‘some’ (OR 1.22; CI 1.11, 1.35) or ‘no’ PA (OR 1.28; CI 1.15, 1.42) reported higher FCR. Compared with non‐smokers, more current smokers reported fear (OR 1.34, CI 1.10, 1.58) and slightly more ex‐smokers (OR 1.11; CI 1.04, 1.21). Conclusions This cross‐sectional study provided novel data showing that colorectal cancer survivors with poorer health behaviours (those with lower activity levels and those who smoked) were more likely to experience FCR. Future research should replicate findings using detailed measures of fear, objective measures of health behaviours and identify directions of associations. © 2016 The Authors. Psycho‐Oncology Published by John Wiley & Sons Ltd.