This collection of studies begins by exploring the development of recognition memory in a group of healthy children and adolescents using experimental memory tests developed as part of this thesis. Various versions of these recognition memory tests were trialled in order to establish age appropriate tests for children aged 6-14 years. In keeping with previous literature in this area, these tests showed relatively stable familiarity memory throughout childhood compared to a steep developmental course for recollection memory.Paediatric brain tumour survivors are known to suffer from significant memory deficits following treatment. However, a clear description of this clinical group's deficits, in terms of recognition and recall (and therefore also familiarity and recollection), has not previously been established. Using standard clinical memory assessments, the current body of work contributes to this area by characterising this population's memory deficits as primarily recall-based, particularly when recalling information presented as prose. A sex difference is also noted; with female brain tumour survivors being significantly more impaired than their age-matched male counterparts. This finding is discussed with respect to the differing neural development of males and females. The experimental memory tests developed with normal children were also administered to a group of paediatric brain tumour patients. They were found to have a varied pattern of performance, including auditory recognition impairments but intact visual recognition, even when the test format incorporated similar foils. Associative memory tests revealed impairments in recollection-based recognition; this effect was dependant on the type of information being associated and the length of the encoding-test delay. A learning intervention was developed (and trialled with healthy children), using a method known as the 'testing effect', in an attempt to enhance recall of prose at long delays in a group of paediatric brain tumour survivors. Structured repeated retrieval was compared to repeated study for prose passages. This was found, with some patients, to be a successful method of improving recall after a delay of one week. Taken together, the work described in this thesis provides further understanding of recognition memory development in healthy children, novel insights into the residual memory function of paediatric brain tumour survivors and an exciting foundation on which to build a rehabilitation programme for this vulnerable group.