Nicotine replacement therapy can double the chance of success for smokers attempting to quit. This observational study aimed to compare quit rates of different formulations of nicotine replacement among clients referred to a smoking cessation clinic in Tehran, Islamic Republic of Iran. Clients entering the study (n = 308) participated in 4 sessions of behavioural therapy, chose a type of nicotine replacement to use (patches, chewing gum, tablets or both patches and gum) and were followed up for 12 months. After 4 weeks of quitting, 88.2% (246/279) reported abstaining from smoking. Self-reported maintenance rates for quitting were 54.9% after 6 months and 36.2% after 12 months follow-up. A significant correlation was found between type of nicotine replacement and quit rate. Use of nicotine patches and chewing gum together had the highest quit rate (95.2%) after 4 weeks and at 12 months follow-up (62.5%). Consuming 2 forms of nicotine replacement in therapy could result in enhanced rates of long-term quitting.