This paper presents a study of 88 British 10–12-year-old children's knowledge of text message (SMS) abbreviations (‘textisms’) and how it relates to their school literacy attainment. As a measure of textism knowledge, the children were asked to compose text messages they might write if they were in each of a set of scenarios. Their text messages were coded for types of text abbreviations (textisms) used, and the ratio of textisms to total words was calculated to indicate density of textism use. The children also completed a short questionnaire about their mobile phone use. The ratio of textisms to total words used was positively associated with word reading, vocabulary, and phonological awareness measures. Moreover, the children's textism use predicted word reading ability after controlling for individual differences in age, short-term memory, vocabulary, phonological awareness and how long they had owned a mobile phone. The nature of the contribution that textism knowledge makes to children's word reading attainment is discussed in terms of the notion of increased exposure to print, and Crystal's (2006a) notion of ludic language use.