Transgenic rubber (Hevea brasiliensis) plants that secrete human serum albumin (HSA) in the serum fraction of rubber latex were generated, using a binary vector pLGMR.HSA (13.8 kb) containing HSA cDNA (1.8kb) with its native leader sequence in Agrobacterium tumefaciens (GV 2260) containing a supervirulent plasmid (pToK47). The transformation success based on production of kanamycin-resistant callus, was calculated as 7.4;. Plant regeneration was 7.1;based on production of embryoids selected on kanamycin containing medium. The frequency of successful establishment of these plantlets in soil was 22;, giving rise to 16 plantlets. These plantlets were screened for the presence of HSA cDNA (1.8kb) and an internal fragment of nptII cDNA (0.7 kb) using the polymerase chain reaction. The presence of the recombinant protein was detected in leaf extracts of transgenic plants but not in controls. Similarly, the presence of the recombinant protein in latex of transgenic Hevea using a two-site ELISA was demonstrated. A production rate of 33 Mg HSA.ml of latex was achieved. Western blot analysis clearly demonstrated the presence of the 68 kDa protein in latex samples from transgenic plants.