The oil and gas (O&G) sector has been touted as being among the greatest lucrative natural resources in propelling Kenya’s economic growth.1 It is axiomatic that the O&G sector anywhere- whether in developed or developing countries brings with it succinct environmental and socio-economic challenges such as land, water and air pollution. This research is mainly concerned with the impact of upstream O&G operations with respect to the regulatory and conceptual underpinnings of the polluter-pays principle (PPP). This principle aims at preventing or otherwise remedying environmental damage through tort/delict liability leading to internalisation of costs; the costs are transferred from Governments to the actual ‘polluters.’2 Owing to the absence of sufficient sanctions in environmental laws and regulations (both regionally and internationally), it has proven difficult for the implementation of the PPP. This underscores the legal and economic importance and encumbrances associated with the upstream petroleum sector. Through historical, analytical and comparative study, this research examines the PPP’s application in upstream petroleum operations in Nigeria and in the United States of America (USA). The difference between these two countries is in the nature of laws and regulations enacted to protect the environment coupled with the institutional enforcement of these laws. While the legal regime in USA is a bit more proactive, dynamic and goal setting; Nigeria’s has conversely been static and largely prescriptive in approach. This will lead to an appraisal of the legal regulatory frameworks in the application of the PPP in curbing the anthropogenic impacts of O&G pollution and the responsibility of the ‘polluter’ thereto in relation to Kenya’s emerging O&G industry. Ultimately, a predisposition will be drawn for Kenya to properly apply the PPP in its O&G related regulatory frameworks by highlighting lessons learnt from Nigeria and USA in order to forester the attainment of both the social and ecological justice stance