Hot-smoke testing in Australia has progressed to the stage where there is an Australian Standard for these tests. The purpose of such tests is twofold: firstly they can validate computer modeling predictions for smoke movement, and secondly they can demonstrate that the smoke control systems and associated fire safety systems function satisfactorily. Hot-smoke tests were carried out in March 1997 at two of Sydney's underground railway stations, namely St James and Museum. The purpose of the tests was to demonstrate that the smoke control systems performed their functions as intended. Tests were carried out in the concourses and on the platforms, and trains ran during the tests so that the effect of moving trains on smoke movement could be observed. A total of five tests were carried out and video recordings were taken of each. This is the first time that hot-smoke tests have been carried out in an underground station with trains running. The paper discusses some of the interesting observations and the problems identified by the tests.