Avian influenza poses an increasing problem in Europe and around the world. Simulation models are a useful tool to predict the spatiotemporal risk of avian influenza spread, and evaluate appropriate control actions. To develop realistic simulation models, valid transmission parameters are critical. Here we reviewed published estimates of the basic reproduction number (R0 ), the latent period and the infectious period by virus type, pathogenicity, species, study type and poultry flock unit. We found a large variation in the parameter estimates, with highest R0 estimates for H5N1 and H7N3 compared to other types; for low pathogenic avian influenza compared to high pathogenic avian influenza types; for ducks compared to other species; for estimates from field studies compared to experimental studies; and for within-flock estimates compared to between-flock estimates. Simulation models should reflect this observed variation so as to produce more reliable outputs and support decision-making. How to incorporate this information into simulation models remains a challenge.