This study was conducted during the second growing cycle of 1991 at Tibaitata Research Center, to examine the influence of seed source on vegetative growth and yield of two lettuce varieties, Great Lakes and Climax. Seed was either imported or locally produced under greenhouse conditions. The study was carried out using RCB design, four treatments (two varieties x two seeds sources) and three replications. Variables assessed were number of leaves, leaf area and fresh and dry weight. Leafarea was 12,751 crnsfor cv, Climax with imported seed; 10,813 cm2 for the same cv. using locally produced seed; 12,335 cm2 for cv. Great Lakes with imported seed and 9,790 cm2 for the same cv. woith local seed. Fresh weight yields were 968.75 gr for cv. Climaxwith imported seed; 619.4 grforthe same cv. using locally produced seed; 742.2 gr for cv. Great Lakes with imported seed; and 568.3 gr. for the same cv. using locally produced seed.