Spinal pain is very common and has considerable consequences for the individual (e.g. loss of employment, disability) as well as increased health care costs. It is now widely accepted that biological, psychological and social factors impact on spinal pain outcomes. The majority of research on social factors has been employment related, with little attention to the influence of informal social support (e.g. families, friends, social groups). The aim of this review is to investigate whether informal social support is associated with the occurrence and prognosis of spinal pain. Prognosis was considered in a broad sense within the biopsychosocial model inclusive of factors such as pain, function, general and psychological health. A systematic search of eight databases was conducted to search for studies who report findings on informal social support in populations with nonspecific spinal pain (i.e. no defined cause). Seventeen articles were identified and a best evidence synthesis was carried out on the data extracted from the studies. Results show that for cross-sectional designs there was inconclusive evidence of a relationship between social support and pain but moderate evidence of a relationship between social support and patient psychological outcome related to prognosis. Evidence of social support as a factor for risk of occurrence was inconclusive with three studies reporting no significant associations with the remaining two studies reporting weak associations. Evidence of an effect of social support and prognosis revealed inconsistent findings. The variation in findings may reflect ongoing difficulties surrounding the conceptualisation and measurement of informal social support.