In order to evaluate the quality of ground water in Al-Mouqdadiya District, Diyala, Iraq, ground water samples were collected from 15 wells in the summer and winter seasons of 2012 and analyzed for various parameters. Physical and chemical parameters of groundwater including electrical conductivity, pH, TDS, Na, K, Ca, Mg, Cl, HCO3, NO3 and heavy metals (Cd, Fe, Pb, Mn, Zn) were determined. Irrigation indices such as, Sodium Absorption Ratio (SAR), Soluble Sodium Percentage (SSP), Residual Sodium Carbonate (RSC), Permeability Index (PI) and Magnesium Hazard (MH) were calculated. Based on the observed results, the TDS of ground water in the study area exceeded the Iraqi guideline for drinking water in 47% while this ground water falls generally in the category of very hard (TH>300 mg/L). For Ca, Mg, Cl, Cd, Pb and Mn it can be concluded with some exception most of the ground water sample were observed to be above of the Iraqi guideline for drinking water. According to the SAR values most of the ground water samples are belong to slight to moderate to severe degree of restriction on use. While the calculated vales of SSP indicated low degree of restriction on the use of this ground water in irrigation. However, the ground water in the study area can be selected as Class III (with 25% maximum permeability) water, which are unsuitable for irrigation purposes according the Permeability and magnesium hazard indices.