Artificial retreats are increasingly being used as a tool for monitoring lizard populations in New Zealand. However, relationships between placement of retreats and skink sightings are not well understood. We investigated how microhabitat around and under artificial retreats influences sightings of common skinks (Oligosoma polychroma) in a grassland habitat in Fiordland. Our dataset comprised 2356 skink sightings from 4100 checks of artificial retreats. Mean vegetation height 0.5 m from retreats was positively correlated with skink sightings, but we did not detect relationships between other microhabitat variables and skink counts. Greater vegetation height may provide enhanced habitat complexity, thus supporting a richer faunal community and higher skink density. Alternatively, skink basking opportunities may be more limited under taller vegetation, making nearby artificial retreats more attractive for their thermal properties. We highlight the importance of considering microhabitat when placing artificial retreats to maximise detections of lizards.