In this study, the rainwater qualities in eight sites located in the oil refinery region within Erbil province were evaluated for irrigation and drinking goals. Rainwater specimens (n = 24) were collected once a time on 21 October 2022. The index for quality of water (WQI), Index for irrigation water quality (IWQI), also Heavy Metals Pollution Indice (HPI) were used in the current study to evaluate the rainfall quality for drinking and irrigation purposes. Physical, and chemical parameters and some heavy metals were determined for assessing the quality of rainwater. The results showed that higher turbidity, pH, hardness, magnesium, potassium, and phosphate were recorded in the nearest sites around the polluted region which was considered higher than the guideline of the WHO organization for drinking uses. The value of the studied heavy metals including iron, manganese, lead, cobalt, arsenic, mercury, and cadmium was higher than the permissible value for drinking purposes in all sites. Based on the calculated WQI, 62.5% of sample sites are poor for drinking, and 37.5% of samples are good for drinking. The nearest sites are poor for drinking water in comparison to remote sites from oil refineries. The values of IWQI varied from 74.06 (low restriction) in site 2 to 55.10 (moderate restriction) in site 4 respectively. According to the HPI of the studied area are polluted and unsuitable for drinking purposes according to the HPI index.