Social work and social services are known to be beneficial to society, but to date no systematic valuation of their contribution has been attempted. The aim of this article is to advance our ability to quantify both the known direct benefits and some of the positive externalities of social work. The authors make the case of why valuation is important for social work and social services. Relying on the rich literature on valuation, the authors provide a review of key valuation methods. The authors then demonstrate how social work and social services can apply each method to assess the value of their contribution to society. The authors conclude with a call for further refinements of social work valuation.