Social protection has emerged as a key driver of development policy at the beginning of the 21 st century. It is widely considered a 'good thing' that has the potential not only to alleviate poverty and vulnerability but also to generate more transformative outcomes in terms of empowerment and social justice. Based on an ethnographic study of the implementation of the Mahatma Gandhi National Rural Employment Guarantee Act (MGNREGA), India's flagship social protection policy, this article takes a critical look at what this policy's 'success' consists of. The study was carried out in Tamil Nadu, a state widely presented as a 'success' in terms of MGNREGA's implementation, and describes who participates in the scheme and how success is understood and expressed at different social and bureaucratic levels. In terms of MGNREGA's outcomes, we conclude that the scheme is benefitting the poorest households -and Dalits and women in particular -especially in terms of providing a safety net and as a tool for poverty alleviation. But the scheme does more than that. It has also produced significant transformative outcomes for rural labourers, such as pushing up rural wage levels, enhancing low-caste workers' bargaining power in the labour market and reducing their dependency on high-caste employers. These benefits are not only substantial but also transformative in that they affect rural relations of production and contribute to the empowerment of the rural labouring poor. However, in terms of creating durable assets and promoting grassroots democracy, the scheme's outcomes are much less encouraging.