The aim of this study was to determine the effects of an educational computer game, Lola's World, on low-performing children's early numeracy skills. Four preschools with 33 children from families of low socio-economic status (M[subscript age] = 5.5 years) took part in this study. Of the 33 children, 23 were split randomly into two groups: an intervention group playing a numeracy game (Lola's World) and an active control group playing an early reading skills game (Lola's ABC party). The remaining 10 children served as a passive control group. The intervention phase lasted three weeks, during which time the children played the games daily for about 15 min. The children's numeracy skills were measured using the Early Numeracy Test. Those children (n = 22) who exhibited low numeracy (i.e. at risk for learning difficulties in mathematics) were included in the analyses. The three groups did not differ in terms of parental educational levels or home languages. They were comparable in terms of nonverbal reasoning and the amount of time spent playing. The Lola's World group improved its early numeracy performance from pretest to post-test. No between-group differences were found. The results are discussed in relation to providing game-based support for low-performing preschoolers.