This study was conducted in an unheated greenhouse during autumn and spring seasons of 2000 and 2001 in order to introduce organic tomato production by testing different organic fertilizers. The tested organic fertilizers were (a) farmyard manure 1 30 tons.ha(-1) + E 2001 + Allgrow Bioplasma, (b) farmyard manure, 50 tons.ha(-1), (c) chicken manure, 30 tons.ha(-1) + E 2001 + Allgrow Bioplasma and (d) chicken manure, 50 tons.ha(-1). In autumn and spring seasons, cv. 191 F-1 and FA 361 were planted on the 12th of September 2001 and 29(th) of March 2001, respectively with a plant density of 1.85 plant/m(2) (120x60x60 cm). Plants were grown in accordance with organic standards throughout production. During the harvest period, fruit samples were taken and analyzed for their quality parameters (average fruit weight, colour, firmness, total dry matter content of fruits and total soluble solids, titratable acidity, pH, EC of fruit juice). The total yield changed between 5.9 and 9.0 kg/m(2) in autumn and 12.6 and 16.2 kg/m(2) in spring. In autumn, farmyard manure, chicken manure + E 2001 + Allgrow Bioplasma and chicken manure ranked in the first statistical group, whereas, chicken manure gave the highest yield in spring. Therefore, well-composted chicken manure is recommended as an organic fertilizer for tomato growing.