Medicated feed-blocks containing 2 mg/kg albendazole were fed for 12 days to ewe-lambs naturally infected with nematode worms in north-west China. The cumulative total average intake of albendazole was 15 mg/kg body weight. This treatment was compared with a single oral drench of 15 mg/kg albendazole and with no treatment. Both albendazole treatments were 99% effective in reducing the total strongyle egg counts. The medicated block was 100% effective in reducing the total trichostrongylid worm count, although only 86.4% of the sheep consumed an adequate amount. The single drench was 97% effective. Under the management conditions available to sheep herders in the northern provinces of China, albendazole-medicated feed blocks used at strategic times could effectively control trichostrongylid nematodes.