Synopsis The present study discusses the definitional aspect and methodology and makes a modest attempt at examining the contribution of unregistered informal segment in terms of employment and income generation; social characteristics of unregistered informal sector; and general characteristics of unregistered informal sector workers including migration pattern, level of living and consumption pattern. The discussion on appropriate rehabilitation programme aiming at the socio-economic upliftment of unregistered informal sector workers also forms an important part of the present study. Besides these, the study also describes the appropriate policy measures so as to improve the socio-economic conditions of workers engaged in unregistered segment of informal sector.