About half of 2,581 low-income mothers reported reading daily to their children. At 14 months, the odds of reading daily increased by the child being firstborn or female. At 24 and 36 months, these odds increased by maternal verbal ability or education and by the child being firstborn or of Early Head Start status. White mothers read more than did Hispanic or African American mothers. For English-speaking children, concurrent reading was associated with vocabulary and comprehension at 14 months, and with vocabulary and cognitive development at 24 months. A pattern of daily reading over the 3 data points for English-speaking children and daily reading at any 1 data point for Spanish-speaking children predicted children's language and cognition at 36 months. Path analyses suggest reciprocal and snowballing relations between maternal bookreading and children's vocabulary.