This study investigates the effects of rich explanation, baseline vocabulary, and home reading practices on English language learning (ELL) preschoolers' sophisticated vocabulary learning from storybook reading. Eighty typically developing preschoolers were pretested in L1 (Portuguese) and L2 (English) receptive vocabulary and were assigned to experimental or control groups. Eight books were selected and paired. Experimental participants heard books read three times over a 3-week period with rich explanations of target vocabulary. Controls heard stories read without explanations. Parents completed questionnaires about the frequency, content, and language of home reading practices. Rich explanation, initial L2 vocabulary, and frequency of home reading make significant contributions to sophisticated word learning from storyreading. Findings have important implications for L2 vocabulary acquisition in ELL preschoolers. (Contains 4 tables.)