This paper investigates the conceptualisation and operationalisation of social support and it's relationship to gender, employment status and social class. Clarification of these relationships is sought in order to better understand associations between social support and health. We used data from the 33-year survey of the 1958 British birth cohort study. Individual items and subscales of practical and emotional support were examined. In general, men had lower support than women and social classes IV and V had lower support than classes I and II. Emotional support, either from personal (for example, from friends or family), or combined with organisational sources of support (such as from a church or a financial institution), showed consistent gender and social class patterns. This suggests that emotional support is a robust concept across socio-demographic groups. Less consistent trends were found for practical support, in that socio-demographic trends depended on how practical support was measured. In particular, it depended on whether both personal and organisational sources of support were examined. Gender differences in social support were large and might therefore be expected to contribute to gender differences in health, whereas social class differences in social support were modest, suggesting a minor explanatory role for this factor in accounting for inequalities in health.