Forty male and 40 female Crl:SD® CD® IGS rats were fed diets containing 0, 40,000, 80,000, or 120,000 ppm tamarind seed polysaccharide (equivalent to 3450.8, 6738.9, or 10 597.1 mg/kg bw/day and 3602.1, 7190.1, or 10,690.7 mg/kg bw/day for males and females, respectively) for 28 days. Animals were observed for adverse clinical signs, body weight, feed consumption, hematology and clinical chemistry parameters, urinalysis values were recorded, and at the end of the study the rats underwent a full necropsy. Functional Observational Battery (FOB) and Motor Activity (MA) tests were performed on all animals. There were no mortalities, no clinical or ophthalmologic signs, body weight, body weight gain, food consumption and food efficiency, FOB or MA findings associated with the administration of tamarind seed polysaccharide. Initial statistically significant decreases in body weight gain and food consumption resolved after the first week and were considered the result of reduced palatability. There were no adverse changes in hematology, coagulation, clinical chemistry or urinalysis parameters in male or female rats considered the result of test substance administration. At necropsy, there were no macroscopic, histopathological findings, estrus cycle, or organ weight changes deemed related to administration of the test substance. Under the conditions of this study and based on the toxicological endpoints evaluated, the no-observed-adverse-effect level (NOAEL) for tamarind seed polysaccharide in the diet was the highest concentration tested of 120,000 ppm (equivalent to 10,597 mg/kg bw/day and 10,691 mg/kg bw/day for male and female rats, respectively).