This study examines the resource status and population dynamics of the giant Malaysian freshwater prawn Macrobrachium rosenbergii in the riverine ecosystem of Sarawak. In term of barrier net catch composition, on average M. rosenbergii formed 41.99% of the total catch. The prawn average catch rate ranged from 7.37kg for Batang (Btg) Kayan to the highest of27.86kg for Btg Saribas per 500m-barrier net per haul. The overall mean catch rate for each river in Sarawak was estimated at 18.33kg (male-54.24% and female-45.76%) which is equivalent to 894 of individual prawn (male-45.88% and female-54.12%). Biomass estimates of prawn are directly proportional to the catch rate and the length of the river, with the highest biomass at 40,537kg contributed by Btg Rajang. Population dynamics (growth, mortality, recruitment pattern and yieldper-recruit) of the giant Malaysian freshwater prawn, Macrobrachium rosenbergii were based on length-frequency analysis using the FiSAT program. Prawns which were captured by different sampling gears (hooks and lines; barrier and cast nets) varied from body weight (total length) of 4g (72mm) to 518g (284mm) for male and 2g (55mm) to 150g (220mm) for female prawns. The size relationship between length (cm) and weight (g) was estimated for 1909 specimens (male) as W= 0.00000645L3.08 (R2 =0.77) and for 4138 specimens (female) as W= 0.00002455L2.82 (R2 =0.71). The growth parameters namely length at infinity, Loo; growth coefficient, K and growth performance index, Φ were 318mm, 0.975year-1 and 4.993 for male and 235mm, 1.350year-1 and 4.872 for female prawn. Analysis of the length frequency data indicated that there are two unequal recruitment peaks per year. The total mortality (Z), natural mortality (M), fishing mortality (F) and exploitation (E) rates were 2.34 year-1, 0.92 year-1 1.42 year-1, and 0.61 year-1 for males and 4.35 year-1, 1.24 year-1.3.11 year-1 and 0.71 year-1 for females. The length at first capture was estimated as total length of 109mm and 95mm for males and females respectively. The Virtual Population Analysis (VPA) of the pooled data of this species indicated that there is a population size of about 24,290 and 40,251 individual prawn at the sampling area and this population was subjected to an average terminal fishing mortality of 1.58 year-1 and 2.6 year-1 for male and female prawns, respectively. The biological yield-per recruit (Y/R) and biomass-per recruit (B/R) analysis for both sex suggested that the current size recruitment to the fishery and effort level, yield per recruit is already maximized.The exploitation rate of prawn population mean was at 28% per annum, indicates that the exploitation rate is below optimum level of exploitation. The overall exploitable potential or maximum sustainable yield (MSY) of M. rosenbergii resource for the riverine ecosystem of Sarawak was estimated at 233,166kg annually with projected revenue of about RM14.33million.