Starting with the observation of a few feeble trails of damage in a sheet of mica exposed to fission fragments some 40 years ago, the discipline based on their correct interpretation has emblazoned a resounding success story in the second half of the 20th century. The spectrum of information revealed by the technique extends from delineating the history of the cosmos over billions of years to observing exotic decays lasting from a minute to a fraction of a second. More, directly useful researches have included medical and biological uses as well as industrial applications. A topic of great current interest is the study of the environmental and health effects of the naturally occurring radon gas. These and other highlights of the track work over the past 40 odd years of the 20th century-with some tentative glimpses of things to come in the 21st-are presented and examined in this review paper. (C) 2001 Elsevier Science Ltd. All rights reserved.