Gross specimens are valuable sources in morphology education. In this study, we investigated how the fixation of gross specimens may be accelerated. For this purpose, whole organ specimens from freshly killed rabbits: extremities, kidney, heart, liver, stomach and uterus were fixed in a mercaptoethanol-formaldehyde mixture for 3-3.5h under the following conditions: 1, at room temperature; 2, at gradually increasing temperatures up to 45-degrees-C; and 3, at a gradually increasing vacuum ranging from 20 kPa to 40 kPa. The results were compared with those of formaldehyde-fixed controls, and the mercaptoethanol-formaldehyde mixture was found to be useful in shortening the fixation time and providing good fixation. Both heat and vacuum enhanced these phenomena.