Growth and mortality rates were calculated for all tree species in the 50 hectare plot established in Pasoh Forest Reserve, one of the remaining lowland mixed dipterocarp forests in peninsular Malaysia. This plot was established in 1986 by the Forest Research Institute of Malaysia, Harvard University, and the Smithsonian Tropical Research Institute. The area is one of the driest and hottest of the southern Malay peninsula, with a one-month dry season and a mean annual rainfall of 1800 mm. The plot is relatively flat with 24 m difference between the highest and lowest points in the plot. Five censuses have been completed, where all trees greater than or equal to 1 cm diameter at breast height were measured and tagged and identified to species. Relative growth rates were calculated for each individual tree using log transformed diameters, annualized by the time interval between census measurements, then averaged within species. Stems that grew more than 75 mm per year or shrunk more than 25% of their initial dbh were excluded from the calculations. The mortality rate constants were calculated using the number of trees alive in the first census, number of survivors in the second census, averaged over the time interval.