In the present study, we report the earliest record of Ixodes sigelos from the late Holocene in Argentina. The tick was recovered from an owl pellet collected within a small mammal sequence in Las Máscaras Cave, Catamarca, Argentina (27 degrees 01'12S'', 66 degrees 44'37''W) and dated at 990 + or - 35 cal yr. Based on bones also present in the pellet, the tick most-likely parasitized a rodent, identified as an Eligmodontia sp., which had been ingested by the owl.