Urologist, Internist and nephrologists' role in the cadaveric organ and tissue donation and transplantation is very important. This study assessed the specialists'' knowledge and attitude toward organ and tissue donation and transplantation. The cross sectional survey consisted of 560 internist, urologist and nephrologists who completed a confidential questionnaire that aimed to assess their existing knowledge and attitude toward organ and tissue transplantation. This assessment was done with questions about attitude and knowledge and ultimate data were analyzed by SPSS and p<0.05 was considered as a significant level. At the present study ,results showed that 435 specialists ( 78%) were inclined with organ donation after death .The most important reason was humanity and helping to each other. whereas , just 140 specialists ( 25%) had positive attitude toward organ donation on alive persons .about the legal aspects of donation just 51 subjects ( 9%) were informed and 32 subjects ( 6%) did not have any information about the legal basis of Organ and Tissue Donation and Transplantation. about the knowledge and financial aspects of donation just 265 subjects ( 47%) and 221 subjects( 40%) were qualified as informed persons. The specialist subjects have an appropriate attitude toward Organ and Tissue Donation and Transplantation. They have significant gaps in legal basis knowledge and financial properties regarding the organ and tissue donation and transplantation. The education of specialist is important as legislation efforts and establishment of transplantation procurement and network.