This paper evaluates the conceptualisation of the informal sector and examines its nature and role in the context of the capitalist growth process, through an examination of two contrasting cases, those of India and South Africa. The first section critically evaluates the conceptualisations that are largely prevalent in the existing analysis. It identifies different informalisation tendencies, some rudimentary and others more dynamic and places the informal sector’s dynamics in the existing trajectory of capitalist accumulation and globalisation. In the second and third sections, it analyses the contrasting cases of India and South Africa, one, where the informalisation tendencies are hugely prevalent and the other where such tendencies are relatively insignificant and attempts to place them in the above context of trajectories of capital accumulation. In the final section, it evaluates certain prevailing notions about the constraints facing the informal sector and the optimism inherent in its desired role and puts forward an alternative evaluation that has bearing on specific policy directions.