The aim of this study was to investigate the possibility to predict by mathematical models seed germination percentage and days to germination on the basis of temperature. Seed from legumes and cereals were used: faba bean (Vicia faba L.), bean (Phaseolus vulgaris L.), pea (Pisum sativum L.), cowpea (Vigna sinensis L.) and some cereals; bread wheat (Triticum aestivum L.), durum wheat (Triticum durum L.), Barleys (Hordeum vulgare conv. distichon and Hordeum vulgare conv. hexastichon), oat (Avena sativa L.), Triticale (Triticale withmack), Rice (Oryza sativa L.), rye (Secale cereale L.), pop corn (Zea mays everta Sturt.), maize (Zea mays indentata Sturt.) and Johnson grass (Sorghum halepense L.) was investigated by mathematical models based on temperature. For this reason a model D = a-(bxT)+(cxT2) produced earlier for predicting the time to emergence in relation to temperature for some vegetable crops was utilized. The final structure of the model did not change for predicting the days to germination of the tried grain legumes while it changed to GP = a+(bxT)-(cxT2) for predicting Germination Percentage (GP) of the crops tried. It was found that the new mathematical models obtained after adapting the present data to the above mentioned model could be applied in terms of the studied parameters. In addition, optimum temperature for seed germination was calculated by using the coefficients T0 = [-b/(2xc)] obtained from the regression models of the days to germination. © 2007 Academic Journals Inc.