In order to study the effect of bio-fertilizers in the form of seed inoculation on the seedling growth of five wheat (Triticum aestivum L.) cultivars, greenhouse experiment was conducted as a factorial based on a randomized complete design with three replications at the Agricultural Institute in the Zabol University, Iran during 2014. The first factor consisted of five cultivars of wheat (Sistan, Kavir, Aflak, Hirmand and Arg) and the second was bio-fertilizer types (phosphate solubilizing bacteria, bio-phosphore, nitroxin, nitrokara, mixed (phosphate solubilizing bacteria+bio-phosphore+nitroxin+nitrokara) and control). Properties of length of shoot and root, fresh weight and dry weight of shoot and root, leaf number per plant and ratio of root dry weight to shoot dry weight were measured. Results showed that the effects of cultivars were significant on length of shoot and root, dry weight of shoot and root, fresh weight of shoot and root, leaf number per plant, the ratio of root dry weight to shoot dry weight of wheat cultivars. In addition, the effects of bio-fertilizers were significant on root length, root dry and fresh weigh, and shoot dry weight. The highest root length (28.7 cm) was observed in nitroxin application. The effects of interaction between wheat cultivars and bio-fertilizers were significant for the dry and fresh weight of the root. The results also demonstrated that the highest fresh weigh of the root (2.8 mg) was observed in bio-phosphore application and Arg cultivar. Based on the results of this experiment the use of the bio-fertilizers in the recommended amount can have a significant effect on the growth characteristics of wheat.