New generation fertilizers called as "bio-fertilizers" or "microbial fertilizers" have been used in soilless crops in the Mediterranean climatic conditions. The aim of the study was whether we can save chemical nutrients in soilless systems by using some microorganisms. Four different commercially available bio-fertilizers used in the experiment; 1) Cocktail mychorriza (Endo Root Soluble) which contained 9 species of mychorriza; Glomus intraradices, G. mosseae, G. aggregatum, G. clarum, G. monosporus, G. deserticola, G. brasilianum, G. etunicatum, Gigaspora margarita, 2) Bacteria (Seranade) which contained Basillus subtilis, 3) Bacteria (Bio- one) which contained 2 species Azoto bacter vinelandi and Clostridium pasteurianum, 4) Microalgae (Allgrow) which contained Chlorella spp. Together with the bio- fertilizers three levels of nutrient solution have been used. Nutrient solution applications consisted of; a) Control treatment contained full strength nutrients, b) The nutrient solution contained 20% reduced all nutrients (macro and micro), c) The nutrient solution contained 40% reduced all nutrients. In the point of yield data, " Mychorriza" and " Microalgae" treatments with reducing nutrients (20 and 40%, respectively) showed increased yields in comparison to their controls. Reduction in nutrient elements with the use of biofertilizers did not significantly reduced plant vegetative growth (total shoot fresh biomass, leaf area and leaf number) and the fruit properties such as weight, length, diameter and total soluble solids. It was concluded that the bio- fertilizers could be used in soilless squash production in order to reduce chemical fertilization resulting in less environmental impact.