The reproductive toxicity of curcumin, turmeric yellow, in Wistar rats was studied in order to generate additional relevant toxicity information for the use of curcumin in humans by oral administration. The two generation reproduction study was designed and conducted in accordance with OECD Guideline No. 416 [OECD, 1983. Guidelines for Testing of Chemicals, Guideline No. 416. Two Generation Reproduction Toxicity Study, adopted on 26th May 1983] and in compliance with Good Laboratory Practices (OECD, 1997 Principles of Good Laboratory Practice for the Testing of Chemicals. OECD, C(97)186/Final). The curcumin, mixed in the experimental diet at the concentrations of 1500, 3000 and 10,000 ppm was fed to three groups of rats, i.e., low, mid and high dose groups, and studied for two successive generations. A concurrent control group received experimental diet without the curcumin mixture. There were no treatment related adverse toxicological effects in the parental animals. No gross or microscopic changes were observed in any of the organs. None of the reproductive parameters were affected and there were no effects on the offspring other than a small reduction in pre-weaning body weight gain of the F2 pups at the highest dose level. It was concluded that the no observed adverse effect level (NOAEL) for reproductive toxicity of curcumin, fed in the diet for two successive generations to rats in this study was 10,000 ppm, which is equivalent to 847 and 959 mg/kg bodyweight (bw) per day for male rats and 1043 and 1076 for females for F0 and F1 generations, respectively. This study was the final toxicology study on curcumin reviewed by the Joint FAO/WHO Expert Committee on Food Additives (JECFA) at the 61st Meeting, 2003. The JECFA group considered that the small body weight reduction in the F2 pups of the highest dose group prevented this from being regarded as a no adverse effect level, and so allocated an ADI for curcumin of 0-3 mg/kg bw based on the intake of 250-320 mg/kg bw in the mid-dose group as the NOEL.