Using Monte-Carlo methods, we have investigated the signal- to-noise ratio obtainable for different fluorescence lifetime imaging methods. Quantum noise limited performance and mono-exponential decays were assumed. We have also investigated the importance of parameter choice and implementation for the different methods. In addition, our simulations were in many cases compared with analytical theoretical investigations. The results from the simulations proved to be in good agreement with the theoretical results. It was found that all the investigated lifetime imaging methods have the potential to produce a high signal-to-noise ratio, but careful attention must be paid to implementation method and parameter choice in order to get optimal results.© (2002) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.