150 Baht - Rama IX 60th birthday of Queen Sirikit

Queen Sirikit was born on August 12, 1932, and her 60th birthday in 1992 was declared a national holiday in Thailand. The date holds additional weight as August 12 had already been institutionalized as Mother's Day throughout the kingdom, a designation tied directly to her person since 1976.

The Royal Thai Mint produced a series of commemorative silver issues across this period, with denominations and specifications calibrated for collector presentation rather than circulation.