This chapter argues that while informal entrepreneurship is important in transition economies (for economic growth, job generation, and welfare improvement), it opens informal entrepreneurs to bribery requests because of their non-ofcial status. With empirical evidence from Vietnam, this chapter demonstrates that the likelihood of bribery is determined by a frm’s attributes. Building on a unique dataset of 352 entrepreneurs in informal frms in Vietnam, this chapter is able to quantify bribery at the frm level and measure key concepts. The empirical fndings confrm the key assumption that entrepreneurs operating in the informal sector of the same country may vary in their propensity to pay bribes due to pressure resulting from (a) factors that are specifc to the frms, or (b) factors specifc to their perceptions of the environment.