Objectives: The main aims of the present study were to explore the illness representations of individuals with multiple sclerosis (MS) and investigate the relationship of these beliefs to outcome. Based on Leventhal et al.'s self‐regulation model, the commonly accepted generic five‐component structure of illness representations including identity, time‐line, consequences, cause, and cure/controllability was used. Design: A cross‐sectional, correlational design was employed for the study. Interrelationships among the illness representation components and the relationships between the components and outcome were explored using Pearson's r. To determine the contribution of the illness representation components to the explained variance in outcome, a series of stepwise multiple regression analyses was used. Method: A total of 99 participants took part in the study. A series of measures were completed to assess (1) illness representations and (2) five specific areas of outcome. Results: Participants' illness representations of MS were consistent with the medical nature and understanding of this illness indicating that they held the perceptions of a strong illness identity, chronic time‐line, no particular cause and no cure. Beliefs in the serious consequences of MS and limited control were also reported. Some important interrelationships among the illness representation components were demonstrated where a strong illness identity, chronic time‐line view and perception of low control were related to more serious consequences. Overall, evidence was provided to suggest that illness representations contribute to outcome. The consequences component was associated with, and contributed to, the explained variance for each of the five outcome areas, indicating that the perception that MS has many negative effects on an individual's life was associated with greater levels of difficulty in all of the outcome areas. In addition, for each of the outcome variables, different combinations of illness representation components explained their variance. For example, higher levels of depression were associated with perceptions of a stronger illness identity, more serious consequences, acute time‐line, and low control. Conclusion: Overall support is provided for the application of the five‐component structure of illness representations to MS and the likely contribution of such beliefs to outcome. The concept of illness representations therefore provides a useful framework for understanding the psychosocial effects of this illness.