Smoking cessation programs can help smokers make a successful attempt at quitting, but many initial quitters relapse over time. This study aims to identify risk factors for smoking relapse and examine the influence of these factors on the dynamic relapse process in an outpatient smoking cessation program for veterans. Baseline information included socio-demographic description, medical and psychiatric comorbidities, smoking history and behavior, nicotine dependence, smoking motives, and confidence in the ability to quit. The intervention involved a 4-session group therapy consisting of cognitive and pharmacological treatments. The 189 initial quitters by program completion were followed via a telephone interview 6 months later. We identified six risk factors associated with relapse within the first 6 months post quit. Furthermore, we described characteristics of the dynamic process of smoking relapse and studied the influence of the identified risk factors on the relapse curve. The effects of these risk factors can be categorized into two patterns. Annual income and age at smoking initiation showed a delayed action that influenced the relapse curve after several weeks post quit, whereas age, number of smoking coworkers, history of schizophrenia, and number of sessions attended modified the relapse process soon after quitting. The information will be useful in targeting veteran smokers who are at high risk for relapse, choosing the optimal time for post-cessation services, and developing strategies accordingly.