A 72 m2 area in Don Martin Marundan, Mati, Davao Oriental was planted to pre-treated and pre-sprouted yam setts arranged in a randomized complete block design to compare the tuber yield and costs when yams are grown with or without trellis. On a 6 m2 area, mean tuber yields of non-trellised and trellised (single strand and double strands of tie wire tied on posts 6 m apart) were not significantly different. With computed tuber yields per hectare however, differences of up to 54 tons may easily be translated to profits. Bulbil yields represented from 16 to 27% of the total yield (tubers + bulbils). Cost and return analysis gave 13.7 and 24.9 % differences in profits when plants were trellised and yam tuber price per kilogram was pegged at P7.5C