An on-farm cultivar evaluation trial for cucumber (Cucumis sativus L.) was conducted to compare differences in plant growth parameters related to fruit characteristics and marketable yield during the summer season. Eight cultivars (Calypso, Cobra, Eureka, Dasher Ii, SMR 58, Marketmore 76, Olympian Fl and Poinsett 76) were transplanted on June 12, 2003 into rows 1.52 m apart and spaced 0.41 m within rows. The trial was established using a randomized complete block design with three replications. Cultivars were harvested on five dates from July 23 to August 10, 2003. Data collected at each harvest included total number of fruits, fresh weight, number of marketable fruits, fruit length, vine length to first flower and fruit. Except for fruit length, differences among cultivars in all measured parameters were significant. New cultivars Cobra and Olympian Fi produced yields that were not significantly (P>0.05) different with common cultivars Calypso and Dasher 2. Cultivar Eureka produced the smallest (202 g) fruit while largest fruits (414 g) were produced by cultivar Olympian F|. Vine length to formation of first fruit was shortest (8.7 cm) with cultivar Olympian Fi and longest (20.9 cm) with cultivar Calypso. In all cultivars, formation of first flower in the vine did not develop into fruit. The study indicates that new and improved cultivars are available to farmers who want to replace old and common cultivars. Best cultivars are Cobra and Olympian F.