Increasing drought and irregularity of groundwater recharge, in conjunction with Iraq's increased dependence on the groundwater, led to increasing important quality assessment of these resources and its different uses; and also rising demand for surface water and the declining reliability. Available evidences relate to each of drinking water and other uses suitability, hydrogeological controls, pollution pressures, and spatial variation, all will be taken in the present review as a critical narrative review. Salinity and mineralization are among the most frequently reported factors, but their intensity varies considerably between groundwater reservoirs. Studies showed a clear spatial variation in groundwater quality across Iraqi aquifers, with existing regions with more suitable conditions and other suffer from greater restrictions related to salinity or local pollutants. The increase in nitrate concentrations in agricultural and wastewater-affected environments contributes to the documented non-cancer health concerns in the Bnslawa area of Erbil, based on 24 years of Dibdiba aquifer records, which demonstrate that degradation may progress over time rather than following a simple spatial gradient. Evidence relating to trace elements has become more substantial, although it remains localized. Studies in Saqlawiya have indicated excesses in lead and cadmium levels, while shallow, conflict-affected wells in Mosul have shown seasonal problems with heavy metals; other groundwater aquifers examined have shown acceptable levels of trace elements. Methodologically, modern Iraqi work increasingly combines water quality indicators, geographic information systems, multivariate statistics, stable isotopes, geo-statistics, entropy weighting, and other modern source-oriented approaches. Differences in sample design, scope of analysis, indicator construction, and reference standard selection continue to limit direct comparisons. Therefore, the literature as a whole does not support the existence of a single national quality category or a standardized treatment plan. The results indicate that groundwater management in Iraq must depend on specific assessment for each aquifer, long term monitoring programs, and linking water quality to hydrological conditions and use, rather than relying on a national unified classification.