Sugar alcohols and other low molecular weight compounds are known to accumulate in plants in response to some abiotic stress factors. A bacterial gene, the mtlD, that encodes mannitol-1-phosphate dehydrogenase, was used to transform Egyptian cotton. Two cotton varieties were used, Giza 86 and Giza 87, long and extra long staple, respectively. The transformation was carried out by particle bombardment of mature, dissected embryos using the Bio-Rad PDS/1000/He gun. The plant expression vector was constructed to contain the mtlD gene driven by the CaMV 35S promotor, and the selectable marker bar encoding phosphinothricin acetyl transferase. Use of mature embryos in this work allowed rapid and direct regeneration of plants without the difficulties of tissue culture induced variations, and circumvented the problems of somatic embryogenesis. Regenerated chimeric R ₀ plants were submitted to preliminary screening by leaf painting using the herbicide basta at a concentration of 200 mg/L. Resistant plants were submitted to PCR and Southern analysis, which showed that the mtlD gene has been integrated into four of the regenerated plants. Assay of mannitol-1-phosphate dehydrogenase was successfully used to determine gene expression in transformed plants as compared to control plants.