A pot experiment was conducted to investigate the effect of sewage water and industrial effluent on germination, post germination growth and heavy metal accumulation in maize at the Agronomic Research Area of Faculty of Agriculture, Gomal University, Dera Ismail Khan, Khyber Paktunkhwa (KPK), Pakistan in 2013. Effluent and sewage water were applied in actual concentration and also diluted with tap water to different concentrations. Results showed that there was linear increase in growth parameters by the application of 100% tap water or at 100% industrial effluent and in some concentrations of sewage water. Maximum leaf area was recorded by applying 100% industrial effluent. Leaf area index was also maximum in treatments where 100% tap water, 100% industrial effluent and 25% tap water + 75% sewage were applied. Similarly, maximum fresh and dry plant weight was recorded in treatments where 100% tap water or 100% industrial effluent was applied either alone or in combination. Plant height and chlorophyll content were maximum in treatments where tap water + sewage water or tap water + industrial effluent was applied in different combinations. However, higher levels of heavy metals (copper, cadmium and lead) were accumulated in the soil by applying sewage water either alone or diluted with tap water in different concentrations. Therefore, it is concluded that although the sewage and effluent had elevated concentrations of some of the metals compared with tap water, the concentrations of such metals in these sources of irrigation water were, however, within the permissible limits for their use as irrigation water.