In a series of trials in Singapore maize in diets for growing and finishing pigs was replaced by different amounts of tapioca meal. Local crossbred pigs were given meal diets in the first 4 trials and imported breeds were given pelleted tapioca diets or maize diets as meal in the last 5. In the first trial 31 pigs, initially aged 95 days and weighing 37.3 kg, were given maize 62, rice bran 25, soya bean meal 8 and fish meal 3%, or maize 34, tapioca 38, rice bran 20, soya bean meal 3 and fish meal 2%. Diets had 15 and 10% crude protein and supplied 3.29 and 3.22 Mcal digestible energy (DE)/kg, respectively. The same maize diet was given in the secound and third trials and was compared to similar diets with 38% tapioca meal and 8 or 12% soya bean meal. In these trials there were 18 and 22 pigs weighing 17.6 and 23.9 kg initially. Trial 4 compared a maize-based diet with 18% protein to one with 38% tapioca and 16% crude protein. In none of those trials was there any difference between groups in weight gain or feed conversion, although the tapioca diets were dusty and unpalatable. In the fifth trial the 62% maize diet with 15% protein was compared with a pelleted mixture of 29% maize and 38% tapioca with 8% soya bean meal and 12% protein. Trials 6, 7 and 8 compared a maize diet with 18% crude protein to one with 38% tapioca and 16% soya bean meal and containing 16% crude protein. Trial 9 tested growing and finishing feeds with 70% maize, 17 or 15% crude protein, or with 60 or 75% tapioca and 16 or 14% crude protein. Between 28 and 16 pigs were used in each test. Pelleted tapioca gave faster growth and more efficient feed conversion than maize and carcass quality was not affected. In tapioca diets protein was less but contained more lysine.