Tanzania Journal of Agricultural Sciences 2000, Vol. 3(1): 55-62A study to evaluate the effect of slllughter weight on carcass characteristics of pigs was conducted using twenty four Landrace X Large lMlite crossbred pigs. Twelve castrates and twelve gilts with average initial weight of 35 ±4.4 kg were randomly assigned to three targeted slllughter weights. Pigs were slllughtered at live weights of 60, 75 and 90 kg and measurements of carcass characteristics were taken. Cost effectiveness of each slaughter weight based on feed cost was determined. Slaughter weight of the pigs had significant (P < 0.05) influence on carcass characteristics. Increase of slaughter weight from 60 kg to 90 kg caused a rise in killing out percentage, loin eye area, carcass length and backfat thicknessjrom 65.0t069.1 %, 24 to 34crrt, 85.1 to 92.3 qnand2.2 to 3.3 cm, respectively. The proportion of kidney fat also increased with slllughter weight. Generally, the weights of carcassjoints, fillet muscle (M. psoas major), liver and kidney as percent of carcass weight decreased with increasing slaughter weight of the pigs (P< 0.05). Castrates had significantly heavier kidney fat and lighter shoulders than gilts but there was no signifi cant sex difference in killing out percentage, carcass length, weights of liver, kidney, fillet muscle, ham, loin and belly, back fat thickness and loin eye area. The slaughter weight of 60 kg was found to be more cost effective than the rest of the slaughter weights and was therefore recommended for areas where there is demand for lean meat.