Multimorbidity challenges quality of life (QoL) in old age. Anticipating and providing social support have been shown to promote QoL whereas receiving support often had detrimental effects. Little is known about which psychological processes explain these effects. This study examines the effects of receiving, anticipating and providing emotional support on QoL, with control beliefs and self-esteem as simultaneous mediators in an elderly multimorbid sample (N = 1415). Anticipating and providing support positively predicted QoL, mediated through self-esteem and control beliefs. Received support negatively predicted QoL, without mediation. Self-esteem and control beliefs can help to explain the relation between QoL and support.