Background: This study aimed to investigate the epidemiology of basal cell carcinoma (BCC) and the probability of having another lesion in patients diagnosed with BCC. Methods: This descriptive-analytical study was conducted from 2015 to 2017, based on the data from patients with definitive diagnoses of BCC in two university hospitals in Birjand. In this study, 85 patients with BCC were selected based on pre-defined inclusion criteria and then divided into two groups, including single and subsequent asynchronous lesions in another anatomic area. In this study, the information was collected by census method from diagnosed patients two years after surgery. The subsequent lesions in other anatomical areas were investigated, then tumor risk factors were compared in the two groups. Results: The mean age of the patients was 67.83 ± 12.29, and the youngest and the oldest patients were 38 and 92 years old, respectively. Among the studied patients, 75.3% had a history of sun exposure. The most common occupations of the patients were farmer, rancher, and housekeeper. Head and neck regions were involved in 96.5%. The patients with subsequent asynchronous BCC in another facial skin region were 10.6% (CI95: 4.06 - 17.14). These patients have been subject to several simultaneous risk factors in their medical history; most of them were farmers older than 65 years. Two patients experienced three lesions in three different anatomical regions at different times. There was no statically significant difference between the two groups regarding mean age (P = 0.47), gender (P = 0.73), pathologic subtype (P = 0.06), and other risk factors (P > 0.05). Conclusions: This study confirms the likelihood of having a subsequent lesion in other anatomical regions in patients diagnosed with BCC. Patients with a history of BCC require prolonged follow-up because of the probability of new BCC developing.