The Nigerian oil and gas sector has suffered a lot of setbacks since the commencement of the production of oil in large quantities. This situation becomes more worrisome for the fact that the oil and gas sector produces petroleum resources which represent the economic mainstay of the country and until recently, was a major employer of labour. This paper examined some factors responsible for the state of decay and dwindling fortunes in the sector and noted that these issues have been pervasive for a long time. The oil and gas sector has been beset by the challenge of non-implementation of or the implementation of ineffective reforms and regulations, the high level of oil theft and pipeline vandalism, systemic corruption and unethical practices by both the local and international players, lack of effective legal and institutional frameworks which should enhance regulatory functions, ineffective leadership, etc. The information used for this paper were gathered from secondary sources. A critical appraisal of the activities of the sector showed that a lot needs to be done by the present Government, especially with the passing of the Petroleum Industry Bill (PIB). The paper adopted the concept of Pockets of Effectiveness to posit that even in the midst of such decay, Government agencies and public organizations can achieve effectiveness but must eschew the mentality of rent-seeking, patronage and clientelism which characterize the oil and gas sector in Nigeria.