Indoor air quality has significant impacts on occupational health, workers' comfort and their productivity. The aim of this study was to assess indoor air quality in a rolling steel plant and to identify corrective measures that could help improve indoor air quality. Many air quality indicators, namely: CO, CO2, VOCs, NOx, SO2, O3, PM10 and PM2.5 were assessed as part of the study. The results obtained showed that higher concentrations of CO, VOCs, were found at the furnace area, while the rolling and quenching process area has the higher concentration of SO2 and CO2 respectively. PM10 and PM2.5 exceeded the international standards in most of the measuring points. Potential negative health effects are expected due to the high temperature and VOCs at the furnace area in addition to the high particulate matters level in all points. Hazard indices (HI) were found to be >1 for all sites indicating possible health risk mainly due to the particulate matter. The respiratory system is the most affected organ, followed by cardiovascular system, then the eye irritation. Based on the potential health risks identified, the paper concludes with some recommendations for protecting workers' health. These include setting local standards for indoor air quality, applying job rotation strategy, periodical medical checks, good ventilation and conducting further studies concerning long-term effect of indoor air quality on occupational health.