A belt tightening device (100/100') for use with a safety device such as a seat belt buckle: a flexible member (12), such as an anchoring length of seat belt webbing, operatively connected to the safety device (34); a housing (102) including a first opening (110) through which the flexible member loosely extends; first and second relatively movable clamping members (160, 162) for causing a portion of the flexible member extending from the housing to be drawn into the housing thereby shortening the remaining length of the flexible member causing a safety belt operatively attached to or part of the flexible member to become more tightly disposed about a user thereof.