Ninety Large White grower pigs were used to determine the most efficient way to hydrothermally detoxify sheanut cake (SNC) and to measure the influence of the detoxified SNC on the performance of grower and finisher pigs. In the first experiment, SNC was boiled in water for 30, 60, or 90 min, dried and included in the pigs' diets at a single level of 20%. There was also another treatment in which the SNC was only steeped in cold water overnight and a control in which the diet did not contain any SNC. In the second experiment, SNC which had been boiled for 90 min was included in the diets at 0%, 20%, 30% and 40%. In both studies, the pigs were fed from an average initial live weight of 20 kg until they attained an average final live weight of 90 kg. In the first experiment the average daily gains (ADG) of the pigs during the grower period were, respectively, 0.46, 0.32, 0.31 and 0.39 kg/day on the control, cold-treated SNC, 30, 60 and 90 min boiled SNC diets (p < 0.01). The corresponding ADGs of pigs during the finisher period were 0.41, 0.36, 0.33, 0.46 and 0.55 kg/day (p < 0.01). The feed conversion efficiencies (FCEs) were, respectively, 6.4, 7.2, 7.5, 7.1 and 6.5 kg feed/kg live weight gain. In experiment 2, the ADGs of pigs during the grower period were 0.44, 0.35, 0.20 and 0.09 kg/day on 0%, 20%, 30% and 40%, respectively, of 90 min boiled SNC diets. The corresponding ADGs of pigs during the finisher period were 0.66, 0.44, 0.27 and 0.13 kg/day (p < 0.01). The FCEs were 4.67, 5.10, 5.90 and 7.10, respectively. The study indicated that the theobromine in SNC is removed by boiling in water and that the level may be reduced to a greater extent by boiling for 90 min rather than for 30 min. It also indicated that a 20% level of inclusion of 90-min heat-treated SNC should not be exceeded for either grower or finisher pigs.