The accident at Bhopal on the night of December 2-3, 1984 was the world's worst accident, resulting in the immediate death of approximately 4,000 and the subsequent death of over 16,000, with life long injuries suffered by over 200,000 followed by genetic mutations to affect several generations of offsprings. The pollution of water bodies is affecting several hundred thousand more. No other recorded accident anywhere in the world has produced even 10% of the above casualties and life-long effects. In this paper, we will briefly describe the accident and the significant effects it has had on regulations, process development and design, training, teaching, RD, etc., all impacting process safety. © 2004 IChemE.