Little research has explored listening comprehension in children whereas reading comprehension has been extensively investigated. One of the reasons for this is that listening comprehension and reading comprehension are highly correlated and it is generally assumed that they draw on the same cognitive-linguistic processes. This assumption has been formalised in the “Simple View of Reading” (Gough & Tunmer, 1986) which states that, once printed text has been decoded, it is understood in exactly the same way as its spoken equivalent. The main aim of the work presented in this thesis was to investigate the assumption that the same skills and processes underpin reading comprehension and listening comprehension by conducting an investigation of the demands made by comprehension in each modality which are over and above those shared with comprehension in the other modality. This issue has not previously been addressed. Children were assessed on both standardised and true/false measures of listening comprehension and reading comprehension and on several variables previously found to predict reading comprehension. Although results varied slightly according to the measure of comprehension used, broad support was found for the Simple View of Reading as a conceptual framework for explaining reading comprehension. It appeared, however, that listening comprehension involved skills which were not shared with reading comprehension. Of particular interest was the finding that, compared to reading comprehension, listening comprehension appeared to make extra demands on children’s inferencing ability. In a further study it was ascertained that this was not simply due to the shared memory demands of the inferencing and listening comprehension tasks. The hypothesis that listening comprehension ability depends on the ability to generate inferences “on-line” whilst listening was tested in a final study but was not supported. In conclusion, the research presented here suggests that listening comprehension is a topic worthy of investigation in its own right and that, for purposes of both research and educational practice, children’s comprehension is best assessed in both modalities.