Giriş: Çevresel insan enfeksiyonu kaynağı olarak son zamanlarda giderek artan düzeyde dikkat çeken ve toplamda 150'den fazla türü olan nontüberküloz mikobakterilere (NTM) verilen önem artmaktadır. Bu çalışmanın amacı, İran'ın kuzeydoğusunda çevresel NTM türlerini izole etmek ve tanımlamaktı. Gereç ve Yöntem: Razavi Horasan eyaletinin 73 şehrindeki içme suyu dağıtım ağları ve su kaynaklarından toplanan 344 su örneği kültür yoluyla incelendi. Nontüberküloz mikobakteriler tanımlaması ayrıca hsp65 geninin polimeraz zincir reaksiyonu amplifikasyonu, sekanslama ve veri analizi yoluyla da yapıldı. İstatistiksel analiz, SPSS 16.0 kullanılarak Pearson korelasyon katsayısı testi ve iki örnek t-testi ile yapıldı. istatistiksel anlamlılık seviyesi 0,05 olarak belirlendi. Bulgular: Nontüberküloz mikobakteriler, kültürde su örneklerinin %10,46'sında (36/244) tespit edilmiştir. En yaygın NTM türü Mycobacterium gordonae (13/36) olarak belirlenmiştir. Diğer saptanan türler M. mucogenicum, M. senegalense, M. gadium, M. genavense, M. simiae, M. frederiksbergense, M. flouranthenivorans, M. neoaurum, ve M. pallens'di. Ayrıca, suda NTM varlığı ile nitrat seviyesi, türbidite, pH ve su kaynağının Introduction: The importance of nontuberculous mycobacteria (NTM), a group including over 150 species, has recently received increased attention as an environmental source of human infection. This study aimed to isolate and identify NTM species in the environment in the northeast of Iran. Materials and Methods: A total of 344 water samples were obtained from water resources and drinking water distribution networks in 73 cities in the Khorasan Razavi province and were examined using culture. Nontuberculous mycobacteria identification was also accomplished by polymerase chain reaction amplification of the hsp65 gene, sequencing and data analysis. Statistical analysis was performed by Pearson's correlation coefficient test and two-sample T-test using SPSS 16.0. Statistical significance was determined at a significance level of 0.05. Results: Nontuberculous mycobacteria were identified in 10.46% of the water samples (36/344) by culture. The most frequent NTM species was Mycobacterium gordonae (13/36). Other Mycobacterium species detected included M . mucogenicum, M. senegalense, M. gadium, M. genavense, M. simiae, M. frederiksbergense, M. flouranthenivorans, M. neoaurum, and M. pallens. Statistically significant correlations were observed between the presence of NTM in water and nitrate level, turbidity, pH, and age of water resource (p<0.001). The relation between NTM presence and depth of the water resource was not statistically significant (p>0.05). Conclusion: It was concluded that NTM water contamination was not very high in this area, but further studies are needed to investigate the sources of contamination and origins of these species.