BACKGROUND: Tobacco use among prisoners is much higher than among the general population. Little is known about changes in smoking-related symptoms during periods of incarceration. The objective of this study is to evaluate changes in smoking-related symptoms during incarceration. METHODS: We recruited 262 inmates from a tobacco-free prison. At baseline, participants were asked about smoking-related symptoms prior to incarceration and then asked about recent symptoms. RESULTS: All symptom scores on the American Thoracic Society Questionnaire (ATSQ) improved during incarceration. Higher ATSQ scores were associated with asthma, depressive symptoms, stress, higher addiction and more pack years of smoking. Greater improvement in symptoms was not associated with smoking status after release. CONCLUSION: Forced tobacco abstinence leads to significant improvements in smoking-related symptoms. However, improvements in symptoms are not associated with smoking behavior changes. Addressing changes in symptoms during incarceration will require further evaluation in smoking cessation interventions for incarcerated populations.