Papaya is one of the most important fruits crops of Kenya. However, in the recent past, papaya productivity and quality have been limited by lack of high quality seeds. Most producers depend on farmer selected and imported seeds for propagation. However, this is not satisfactory since few farmers can afford imported seeds due to their high price. On the other hand, most of the farmer selected seeds give rise to trees with inferior fruit quality and are susceptible to diseases. The above mentioned challenges necessitated the development of new Jomo Kenyatta University of Agriculture and Technology (JKUAT) papaya lines with superior qualities to help boost fruit production. So far, the new JKUAT papaya has been evaluated only at JKUAT main campus in Kiambu County. This study evaluated the performance of newly developed JKUAT papaya lines (Line 1, 5, 6 and 7) in different agroecological zones of Kenya. The study sites were JKUAT (upper midlands zone), Nkubu (upper highlands zone), KALRO Mwea (upper midlands zone) and Mitunguu irrigation scheme (upper highlands zone). The results on morphological, fruiting and biochemical quality showed significant differences. The total number of fruits varied significantly where line 1 had the lowest number (84 fruits) in JKUAT and the highest number was recorded in line 5 (134 fruits) in KALRO, Mwea. The fruit weight varied significantly and ranged from 1.2 kg in line 5 in JKUAT to 2 kg in line 7 in KALRO Mwea. The total soluble solids (TSS) varied significantly from 8.3% in line 7 in KALRO Mwea to 13.7% in line 5 from Nkubu. The results revealed that new lines had good productivity and they should be commercialized in Kenya. However, there is a need to determine the performance of the newly developed papaya lines under heat and water stress conditions.