Aims The duration of partial remission of Type 1 diabetes is associated with the degree of initial metabolic disturbance and features of insulin resistance. Cigarette smoking decreases insulin sensitivity, but its influence on the length of remission is unknown. Therefore, this study assessed the relationship between cigarette smoking and duration of partial remission in adults with newly diagnosed Type 1 diabetes. Methods We recruited 149 patients (48 women and 101 men, aged 1635 years, median age 25 years), admitted to a teaching hospital with newly diagnosed Type 1 diabetes and followed them for a median period of 1 year and 9 months. We introduced intensive insulin therapy in multiple injections (basal-bolus) in all patients. We defined partial remission as an insulin dose of = 0.3 U/kg body weight/24 h, an HbA1c value < 53 mmol/mol (7.0%) and a random serum C-peptide concentration over 0.5 ng/ml. Cigarette smoking was determined by self-report. Results Of 149 patients, 68 (46%) fulfilled the criteria for partial remission at 1 year after diagnosis of diabetes. Fewer patients who were in partial remission at 1 year smoked (19/68, 28%) than did patients that were not in partial remission (41/81, 51%). In logistic regression analyses, non-smoking was associated with remission at 1 year independent of age, sex, HbA1c and presence of diabetic ketoacidosis, all measured at onset of diabetes (OR 3.32, 95% CI 1.427.75, P = 0.005). Conclusion Relative to individuals in this study who smoked, those who did not smoke at diagnosis of Type 1 diabetes experienced a longer duration of partial remission.