Water quality has been a matter of concern in civil engineering projects.Most specifications require the use of potable water because its chemical composition is known and well regulated. In some situations where potable water is not ready available, many water types which are unacceptable for drinking may be satisfactorily used in concrete, such as the well water. In this study, Well water is being investigated the feasibility of using well water as a mixing water in concrete. Water samples were obtained from three different wells. The chemical properties of these samples were investigated in the laboratory. Eight mixes were prepared from two types of cement (ordinary and sulfate resisting Portland cements) and these samples of well water as well as distilled water in order to make a comparative study. The concrete specimens were cured and tested for compressive,splitting tensile and flexural strengths at(3, 7, 28) days. The results, when compared with the results of control mixes (made with distilled water), showed that same effect of well water on the concrete strengths approximately. Therefore, the well water with acceptable limits in its chemical analysiswas suitable for use in production of concrete with acceptable strength.