Greenhouse cultivation plays an important role in agricultural production owing to grow rapidly, produce higher yields in shorter times and out of season in smaller areas. Heavy metal has threatened soil, water, enviroment and sustainable agriculture because of with intensive cultivation and high input (pesticides, fertilizer, water) in greenhouse. Heavy metal pollution which is the most important of inorganic pollution parameters, is a worldwide problem in agricultural lands and poses a long-term risk to environment due to toxic effect and accumulation features. The aim of this study was to determine heavy metal levels of irrigation water in greenhouse in Tokat provience, Turkey. For this purpose, in total 60 water samples were taken from different 30 greenhouses. The levels of heavy metals (Ni, Cd, Cr, Pb, Cu, Zn) were determined by using inductively couple plasma optic emission spectrometry (ICP OES) according to standard methods. The levels of heavy metals in analyzed samples were found to be lower than permissible levels of FAO-WHO.