This study was carried out to compare the efficacy of two suspensions (5% and 15%) of netobimin against Dicrocoelium dendriticum in naturally infected sheep. Fifteen Merino sheep, 4 to 7 years old, were used in this survey. Animals were divided into three equal groups each of five sheep on the basis of bodyweights and D. dendriticum egg counts in per gram faeces. Group A and group B sheep were treated orally with 5% and 15% suspension of netobimin, respectively: both at a dose rate of 20 mg kg(-1). Group C sheep were left untreated as controls. Twenty-one days post-treatment all sheep were slaughtered for post-mortem examination. All D. dendriticum from the liver and gall bladder were recovered and counted. The results showed that the efficacy of 5% and 15% suspension of netobimin was 90.80% and 91.50%, respectively, and the use of 15% suspension in sheep is discussed. (C) 2008 Elsevier B.V. All rights reserved.