Four experiments are described in which the efficacy of an experimental 5% injectable solution of rafoxanide was evaluated against various adult and immature helminths in cattle. Subcutaneous injection at a dosage of 3 mg/kg live mass resulted in the following reductions in mean worm burdens: adult Fasciola hepatica, 82,6%; adult Fasciola gigantica, 99,8% immature Paramphistomum microbothrium, 10,1% adult Haemonchus placei, 99,6%, third stage H. placei, 73,7%; adult Bunostomum phlebotomum, 99,8%; adult Oesophagostomum radiatum, 99,9%; and fourth stage O. radiatum, 76,9%. At 5 mg/kg live mass, rafoxanide solution was 97,5% and 99,2% effective against 8-week old F. gigantica and third stage H. placei respectively and at 7,5 mg/kg, 92,4% against 6-week old F. gigantica.