The family Anomalepididae which includes four genera and around 15 species has been less studied than all other Scolecophidia. Liotyphlops beui is one of the most collected snake species in São Paulo city. We studied the seasonal and daily surface activity pattern of this fossorial snake. The snakes were collected mainly in rainy and warm periods, indicating a highly seasonal activity. The minimum temperatures explain this pattern more accurately. The decrease in activity of L. beui during the dry and cold season is more pronounced than in any other snake from southeastern Brazil. The morphological and ecological characteristics may explain why this species is collected in lower numbers in the dry season than other snakes from the same region. Activity in L. beui occurs predominantly during the early dark hours, usually between 19:00 and 21:00 h. This short activity period may be determined by light intensity and temperature, although prey and/or predator activity may also influence this activity pattern.