Abundance of chum salmon Oncorhynchus keta that returned to spawn in the Chena and Salcha rivers during 1992 was estimated in August using mark-recapture techniques. A boat-mounted electrofishing unit equipped with pulsed-direct current was used to capture chum salmon during the marking events. Carcasses of chum salmon were collected and examined for marks during the recapture events. Estimated abundance of chum salmon in the Chena River was 6,083 fish (SE = 1,857 fish), with 3,359 females (SE = 1,034 fish) and 2,724 males (SE = 842 fish). Estimated abundance of chum salmon in the Salcha River was 14,057 fish (SE = 3,813 fish), with 7,945 females (SE = 2,167 fish) and 6,112 males (SE = 1,674 fish). Age and size composition estimates from both rivers indicate that age 0.4 fish (1987 brood year) predominated. Precision in estimates of abundance in both rivers was compromised by bias due to unequal recapture rates between sections of river.