A telephone survey of farmers was conducted to determine current internal parasite control practices on sheep farms in Spain; the farmers were interviewed by their veterinarians. Anthelmintic choice was largely on veterinary advice and dominated by benzimidazoles and macrocyclic lactones. Anthelmintic rotation was separated into: no rotation (42% of farms); annual rotation (36%); rotate within year (20%); and rotate every second year (2%). The mean annual number of treatments varied subtly by region; ewes and rams 1.6-2.1, replacement lambs 1.7-2.1. Anthelmintics are administered primarily during spring and early summer (47% of treatments), and autumn (41%). Thirty-two percent of farmers introduced sheep to their properties and more than half did not quarantine drench the arrivals.