This thesis was concerned with determining the scope, nature and impact of pain on quality of life (QOL) among a community-based sample of people with multiple sclerosis (MS). An analysis of the research literature on pain in MS reveals that pain is a significant problem which has historically been underinvestigated and is currently poorly understood. The vast majority of the published literature consists of prevalence studies, descriptive research and clinical reports. Where available, empirical data are often limited by methodological and analytical problems such that substantive conclusions about the scope and nature of MS-related pain remain unclear. Among the most fundamental issues is the extent to which pain is problematic in a population which is already impaired by other physical disabilities. Little is known about how pain contributes to MS-related disability, distress and QOL. Moreover, research examining the psychosocial aspects of MS-related pain is noticeably absent. It is clear that there are substantial gaps in the literature and that many basic questions about the scope, nature and impact of pain problems among individuals with MS remain unanswered. Thus the primary aim of this study was to begin to fill some of these gaps by systematically investigating the following research questions: (1) What is the prevalence and nature of pain experienced by people with MS? (2) What is the impact of pain on the QOL of people with MS, over and above the impact of disability itself? (3) To what extent do physical and psychosocial factors influence adjustment to chronic pain in people with MS? (4) What meaning is given to the pain experience by people with MS? The present study utilised a multimethod research design involving cross-sectional postal survey, structured in-person pain interviews and focus groups. Survey respondents were a 219-person sample recruited from the Queensland MS Society membership database via systematic random sampling. All participants completed a piloted questionnaire containing questions about their demographic and clinical characteristics, validated measures of QOL and MS-related disability, and a question on whether or not they had experienced clinically significant pain in the previous two weeks. Respondents who reported pain then completed face-to-face structured pain interviews assessing pain characteristics (viz. intensity, quality, location, extent and duration), pain-related beliefs and coping strategies, and pain management techniques used. Four focus groups were also conducted that included 32 people with MS living in the community. Study participants were a purposive sample drawn from four MS support groups located in the South-East Queensland region. Pain was found to be common with some 67.1% of the sample reporting pain during the two weeks preceding the study. Comprehensive pain assessment revealed that a substantial subset of these individuals experience chronic pain conditions characterised by moderate-to-severe pain intensity. Pain prevalence and intensity were found to be strongly correlated with QOL: physical health, psychological health, level of independence and global QOL were more likely to be impaired among people with MS when pain was present, and the extent of impairment was associated with the intensity of pain. Moreover, these relationships remained significant even after statistically controlling for multiple demographic and clinical covariates associated with self-reported QOL. Pain-related beliefs and coping strategies were also associated with and explained a significant proportion of the variance in adjustment to pain among people with MS, over and above that accomplished by demographic and MS-related variables and pain intensity. Finally, qualitative data analysis revealed four broad conceptualisations of the experience of chronic MS-related pain including: pain is pervasive, nobody understands, I'm fine, and always a factor in the equation. These findings suggest that for people with MS, pain is an important source of distress and disability over and above that caused by neurological impairments. These data also lead to the hypothesis that recognition and effective treatment of pain would improve the QOL of people with MS, irrespective of their level of neurologic disability. Although correlational, the findings provide support for a biopsychosocial model of pain and adjustment to pain in people with MS.