Rafflesia tuan mudae Beccari known as holoparasitic species produces gigantic flower, which is endemic to Borneo in Sarawak, Malaysia and Kalimantan, Indonesia. Limited information on R. tuan mudae reproductive characteristics has hindered the design of effective conservation and management plans. In this study, to quantify the growth rate, mortality, and recruitment rate of flower buds and flowering phenology of R. tuan mudae, a total of 264 buds were tagged and monitored monthly from March 2016 to February 2017 at four study sites in Gunung Pueh National Park, Sarawak. A total of 216 flower buds died before flowering and 29 ones survived at the end of study period. We also recorded 19 flowers and 163 of newly recruited flower buds. The growth rate of flower buds in R. tuan mudae was found to be slow like other species of Rafflesia. Possible factors affecting population dynamics and flowering phenology of R. tuan mudae such as mean rainfall and average temperature will be discussed. Findings from this study would be helpful in managing Gunung Pueh National Park areas and as a step for conserving R. tuan mudae which is listed as Totally Protected Species in Sarawak Wildlife Protection Ordinance, 1998.