Purpose: Few studies have compared the effects of immediate loading on implant prognoses in smokers and nonsmokers. The aim of this prospective study was to evaluate the long-term success of immediately loaded platform-switched implants placed in smokers and nonsmokers with edentulous jaws. Materials and Methods: Platform-switched implants were placed using the same treatment protocol in the healed edentulous jaws of two groups of patients: group A patients had smoked at least 20 cigarettes a day for more than 10 years, and group B consisted of nonsmokers. All implants were loaded immediately with provisional fixed prostheses, and definitive cement-retained restorations were delivered 4 to 6 weeks later without removing the abutments. In a standardized follow-up protocol, the implants were evaluated clinically and radiographically at the start of loading, 4 to 6 weeks later, and annually thereafter. Results: Sixty-six implants (36 in the maxilla and 30 in the mandible) were placed in eight smokers. Twelve nonsmokers received 97 implants (55 in the maxilla and 42 in the mandible). During an average loading period of 62.53 (± 44.13) months for the smokers and 98.20 (± 19.53) months for the nonsmokers, three implants failed. Two failed in group A (one because of overloading and one because of peri-implanitis) and one failed in group B (overloading), resulting in implant survival rates of 97% and 99%, respectively. No significant differences were found between groups regarding plaque, bleeding, probing pocket depths, or crestal bone loss, either mesially or distally, resulting in success rates of 92.42% for group A and 98.00% for group B. Conclusions: Long-term clinical outcomes for immediately loaded platform-shifted implants placed in heavy smokers appear to be comparable to those for nonsmokers if the abutments are placed on the day of surgery and never removed.