Incidental word learning is influenced by context, task, and reader characteristics. The present study aimed to determine the contribution and interactions of these factors for fifth-grade students. The focus was on contextual differences: words' meanings are inferred from local or global contexts. This effect was tested as a function of task: gap filling, inference questions, and summary writing in comparison with the single reading of the text. Regarding the reader, the contribution of general vocabulary knowledge and working memory was determined. The results showed that words are better learned in local than global contexts, and that the higher-level tasks (inference questions and summary writing) enhanced word learning beyond the single reading of the text, whereas gap filling did not. General vocabulary knowledge was related to overall incidental word learning from text, whereas working memory contributed to vocabulary gain from answering inference questions. One can conclude that incidental word learning from text is optimal in local contexts, when doing higher-level tasks and when general vocabulary is high.