Lung cancer has been linked to exposure to the naturally occurring ionizing radiation, radon gas (22Rn). Radon is ubiquitous in our environment. However, the level of concentration of this gas is influenced by the geological, geographical, meteorological conditions of a particular environment. The indoor radon concentration is also influenced by factors such as air-conditioning system, ventilation, age of building etc. In this study, the level of indoor radon was measured in 55 offices located within Abia State University, Uturu in South Eastern Nigeria using a Corentium digital radon detector. Uturu is well known for vegetation with high granitic and sedimentary rocks. Offices were chosen to vary between those that are furnished with air conditioning systems and those that are without such facility. Measurements were taken between December 2017 to June 2018. The result of the measurements showed that the indoor radon concentration for all the offices varied between. This value is lower than the intervention level of recommended by International Commission on Radiological Protection (ICRP). The annual effective dose for the offices ranged from which is below the recommended ICRP intervention level of. Hence, there is low risk of adverse health effect and lung cancer induction to the staff of Abia State University.