This study was carried out in the plastic covered greenhouses belonging to the Institute of Solar Energy, Ege University, in Turkey, during the spring growing season of 2000. Cucumber (cv. Sardes) was used as the plant material, aiming compare natural pesticides with synthetic pesticides in regard to yield and fruit quality. Garlic barrier, hot pepper wax, Organica neem oil, Neem Azal T/S, Herba vetyl, Savona and soft soap were used as the natural pesticides. The treatments comprised applications of (a) synthetic pesticides (control), (b) garlic barrier as a repellent and other natural pesticides, (c) hot pepper wax as a repellent and other natural pesticides, (d) and the natural pesticides excluding the repellents. No significant differences were found between the natural and the conventional pesticides in respect to yield and fruit properties such as total soluble solids, titratable acidity, pH and electrical conductivity of fruit juice, fruit firmness and fruit colour.