Surgical treatment, the minimal volume of which is lobectomy with mediastinal lymphadenectomy, is considered the method of choice in functionally operable patients with non-small cell lung cancer (NSCLC). Objective: to retrospectively assesse the results of surgical treatment in patients with peripheral NSCLC (T1—2aN0M0) in view of the volume of surgery and a number of other clinical and morphological factors. Subjects and methods. The analysis included 363 patients with a peripheral NSCLC of less than 4 cm without lymph node metastasis, who had undergone lobectomy (91.2%), segmentectomy (3.6%), or nonanatomic lung resection (5.2%). The patients’ mean age was 59.8 years; there was a preponderance of males (80.2%). The tumor was more often localized in the right lung (54.0%) and upper lobes (66.1%). Stages IA (pT1а—bN0M0) and IB (рT2aN0M0) were diagnosed in 188 and 175 patients, respectively. There was adenocarcinoma in 47.4% of the patients, squamous cell carcinoma in 39.2%, large cell carcinoma in 5.8%, adenosquamous carcinoma in 6.0%, and mucoepidermoid carcinoma in 1.6%. Results. Postoperative complications were diagnosed in 10.2% of the patients; the mortality rates were 1.4%. The 5-year overall survival rates for the patients were as high as 71%; those for Т1a—b and Т2а were 76.1 and 67.1%, respectively (p>0.05). The highest rates were seen for squamous cell carcinoma (77.5%) and adenocarcinoma (68.0%; p>0.05); lower rates were observed for large cell carcinoma (50.4%; p=0.03). A poor prognosis was established in patients after nonanatomic lung resection (43.8%; p<0.001) compared to those following transthoracic lobectomy (72.4%) and segmentectomy (81.5%; p>0.05). The 5-year overall survival rate after video-assisted thoracoscopic lobectomy was comparable with that following thoracotomies. A multivariate analysis confirmed that the morphological type of NSCLC and the volume of surgery had a negative impact on the long-term results of the latter. Conclusion. The poor clinical and morphological prognostic factors for surgical treatment in patients with NSCLC (Т1—2аN0M0) should include large cell lung carcinoma and an operation as nonanatomic sublobar resection. Segmentectomy may be considered the standard treatment volume in only patients with NSCLC (T1aN0M0).