Objective In the present work, the chronic toxic effects of the transgenic rice T2A-1 carrying cry2A* gene was evaluated on Sprague-Dwaley rats through a 52-week feeding study. Methods One hundred and forty-four rats were randomly divided into 3 groups according to body weight. Transgenic rice T2A-1 and parent rice were formulated into diets at high levels of 60.75% during the growth period and 66.75% during the maintenance period, respectively. AIN-93 diet was used as a nutritional control. Animals were fed with the corresponding feed for 52 weeks. Cage-side observation, animal body weight, food intake, food utilization, hematology, serum biochemistry and urine analysis were carried out routinely. At the end of the administration, all survived animals were anatomized and histopathological examination were conducted. Results The main nutrient contents of the transgenic rice were similar to the parent rice. Throughout the experimental period, the trends in body weight, food intake and food utilization rate were similar in all groups. Although statistical significance was observed in some indexes of hematology, serum biochemistry and urine analysis of the transgenic rice groups as compared with the parent rice group, they were not considered as treatment-related. Histopathological examination showed some spontaneous lesions in all groups with no significant difference among them. Conclusion The result of the current 52-weeks chronic toxicity study of transgenic rice T2A-1 exerted no unintended adverse effects on rats.