Objectives To evaluate the association between cancer screening counselling provided by medical doctors to their patients and each doctor's own anthropometrics, lifestyle, cancer screening practices, and personal and family history of cancer. Design Prospective cohort study. Setting Substudy including physicians participating in a Spanish cohort study with open enrolment. Participants Among 22 800 participants in the cohort as of May 2018, there were 2371 physicians who had replied to the cohort baseline questionnaire, had an email account and were younger than 65 years (retirement age in Spain). From this subsample, 890 replied to an online questionnaire focused on their clinical practices related to the counselling provided to their patients and to their prescription practices of preventive medications. Their mean age was 51.7 (SD 9.4) years and 48% were women. Outcome measures Frequency of counselling given to their patients on specific practices of breast, colorectal and prostate cancer screenings. Results Counselling on cancer screening to their patients was provided by 65% of physicians in a scenario of colorectal cancer, 59% for prostate cancer and 58% for breast cancer. More frequent cancer screening counselling was associated with the specialties of family medicine (OR=9.4, 95% CI 5.1 to 17.1) and internal medicine (OR=2.9, 95% CI 1.5 to 5.7) as compared with other specialties. Recommending cancer screening was associated with more frequent counselling on smoking cessation (OR=3.7, 95% CI 2.6 to 5.4), having personally attended colorectal cancer screening (OR=2.2, 95% CI 1.1 to 4.7) and prescribing blood pressure medication more often than their colleagues (OR=2.1, 95% CI 1.2 to 3.7). Conclusions Among medical doctors, cancer screening counselling was provided to their patients more frequently for doctors with family medicine or internal medicine specialties and for physicians who regularly offered counselling on certain lifestyle behaviours, and those having personally attended colorectal cancer screening. Doctors' own personal practices and knowledge of healthy lifestyles may help doctors to more frequently provide counselling on cancer screening to their patients.