Background: Informal caregivers are those providing care, which exceeds that which is typically provided, to a relative or friend with care needs. Informal caregiving constitutes the backbone of a society’s care supply and with ageing populations the need for informal care is growing. We know little as to why caregivers start caring and continue doing so, yet understanding of motivations and willingness to provide care is important if informal caregivers are to be supported. However, both motivations and willingness are inconsistently defined making it difficult to compare the empirical findings that do exist. Methods: This paper reviews and synthesises thinking about the theoretical constructs of motivations to provide care and willingness to perform informal care, and presents those in relation to existing theoretical and empirical literature. Results and Conclusions: Theoretical reflections based on various motivational frameworks and available empirical data are presented to illustrate that: caregiving motivations should be conceptualised as multifaceted and multiply determined; intrinsic and extrinsic motivations should not be treated as antagonistic and can occur simultaneously; the commonly applied model of extrinsic/intrinsic motivations is oversimplified and omits consideration of the diversity of caregiver motives; other motivational models can be discerned in the context of the empirical research; there are differences between motivations and willingness to provide care with the latter being more consequent to the motives; both should be considered dynamic in nature; and finally, that the two constructs may not inevitably lead to actual caregiver behaviour. The implications of these theoretical reflections for methodology and research as well as their relevance for practice and policy are indicated.