Of five moulds that were cultivated in a medium containing beet pulp, Trichoderma reesel was superior in protein production (34%) and in conversion of pulp to proteins (18% w/w). Protein ylelds were improved by up to 49% by pre-treatment of the beet pulp, adjustment of the solld/llquid and liquld/solid ratios, the incubation period, nitrogen level and addition of some trace elements as well as with inoculum size. The protein obtained contained all essential amino acids and compared favourably with those of the FAO guldeline and of soy bean oll meal.