Objective Hypertension is an emerging non-communicable disease in developing countries. Due to its silent nature and serious complications, active screening is essential in order to prevent complications. For instance, premature mortality from cardiovascular diseases could be prevented by the effective control of hypertension. The aim of this study was to determine the prevalence of undiagnosed hypertension among Nuba ethnic group living in Atbara city, north Sudan and to identify the associated risk factors. Subject and methods All consenting 500 adults from Nuba tribe who live in El Wihda District, Atbara were included. Blood pressure (BP) and body mass index were measured. Standard interviewing procedures were used to record medical history, sociodemographic data, and lifestyle characteristics. Results Among the 500 participants, females were 364 (72.8%) and males were 136 (27.2%). The overall prevalence of undiagnosed hypertension was 49.4% (30.8% stage 1 hypertension and 18.6% stage 2 hypertension). In addition, 41% of the population was having prehypertension. The significant risk factors for high BP were: male sex, age above 45 years, overweight, illiteracy, and alcohol consumption. Conclusion Undiagnosed high BP is very common among Nuba ethnic group; therefore, active screening and early management are recommended to prevent complications. ARTICLE HISTORY