A novel class of inhibitors of pestiviruses (5-substituted 2-phenyl-5H-imidazo[4,5-c]pyridines) is described. Modification of the substituent in position 5 resulted in analogues with high activity (EC50 < 100 nM) and selectivity (SI > 1000) against the pestivirus BVDV (bovine viral diarrhea virus).