The petroleum industry is generally regarded as one of the most secretive sectors and Bangladesh's petroleum sector is no exception. In this thesis I examine how transparency, supposedly an opposite notion to secrecy, works in Bangladesh's petroleum sector. Of the many possible aspects of transparency, the study mainly focuses on its information flowfacilitating and accountability-enhancing aspects, and on two benchmarks of transparency, namely, access to information and public participation in the decision-making process. Examination of field data through the lens of these two benchmarks leads to the finding that within a legal framework, both transparency-promoting and transparency-inhibiting modes of approaches can coexist; it is actually the actors whose actions determine the overall transparency outcome in this sector with the actors preferring one mode over the other. It is also found that factors such as perceptions, attitudes, cultures and even prejudices of the actors involved in the sector can influence the actions of the actors when they apply rules and procedures in the petroleum sector on a day-to-day basis. Depending on such influence the actors' actions or the positions they adopt may either impede or promote transparency in practice. However, it has also been found that while the petroleum industry's approach to transparency may not be on a par with the benchmarks of transparency that this research set out to explore, the industry indeed has its own kind of transparency occasions. The research examines each of these occasions, exploring their meeting and departing points with the transparency benchmarks, and looks for answers and explanations. The findings, therefore, may help develop a nuanced understanding of the workings of the petroleum sector generally," and its interplay with transparency particularly.