This multicenter, randomized, open-label clinical trial was conducted to determine whether the combined use of nicotine patch therapy and a nicotine nasal spray would improve smoking abstinence rates compared to either treatment alone, without behavioral counseling. Data were collected at 15 regional cancer control oncology centers within the North Central Cancer Treatment Group. Of the 1384 smokers randomized to the study, 20% were abstinent from smoking at 6 weeks and 8% were abstinent at 6 months. At 6 weeks, the 7-day point prevalence smoking abstinence rate for the patch alone (21.1%) was superior to the spray (13.6%) but was significantly lower than the rate for combination therapy (27.1%). At 6 months, the 7-day point prevalence abstinence rates were not significantly different among the three groups. Combination nicotine nasal spray and nicotine patches were delivered safely in a nonspecialized outpatient clinical setting and enhanced short-term smoking abstinence rates, but these rates were not sustained at 6 months.