Artesian wells are sources of water from the late Pleistocene era. They are in common use in Krakow, in southern Poland, where five years ago limited studies were carried out, the results of which disputed the potability of water from some of the wells. This paper presents complex studies carried out at the end of 2012 concerning the pollution and composition of water samples from nine artesian wells. We studied smell and taste, color, turbidity and conductivity, pH levels, hardness, oxygen concentration and demand, total organic content, compound concentrations (NH{{4}}^{+}, NO{{2}}^{-}, NO{{3}}^{-}, Br^{-}, Cl^{-}, benzene, ethylbenzene, xylene, toluene), element concentrations (Al, Ca, Cd, Cu, Fe, Hg, Mg, Mn, Pb, Zn) and the quantity of bacteria. In only on well was water fit for human consumption. In other cases, numerous parameters were above the permissible limits. Most often, the parameters of color, turbidity and concentrations of Fe and NH{{4}}^{+}, exceeded the acceptable levels. In one well the concentration of benzene also exceeded the maximum permissible level. The significance of the differences in the levels between wells shows that aquifers mix either very slowly or not at all.