This study examines the role of rules of procedure in mitigating the un intended consequences of Public Interest Litigation (PIL) with reference to the Standard Gauge Railway in Kenya as a case study. In other jurisdictions, PIL has arguably brought about social transformation and protection of social and economic rights. In Kenya, the Chief Justice formulated the Constitution of Kenya (Protection of Rights and Fundamental Freedoms) Practice and Procedure Rules 2013 that will make it possible to implement Article 22 of Constitution. PIL therefore offers a real opportunity to advance, shape and implement policies in the public sphere as expounded in the provisions of the Constitution of Kenya, 2010. These include the national values under Article 10 and which binds all State Organs, State Officers and Public Officers whenever any of them applies or interprets this Constitution, enacts or applies or interprets any law, makes or interprets public policy decisions. Article 258 allows individuals to bring actions in public interest while Article 259 allows a person to contemplate any type of litigation as long as it promotes values, rule of law, development of the law and good governance. The thesis reviews the role of rules of procedure in other jurisdictions such as United States of America, India, South Africa and Kenya for comparison purposes. Despite many positive outcomes of PIL, this paper argues that there are occasions where the objectives of PIL are outweighed by its un intended consequences. With reference to the development of the Standard Gauge Railway, it will be illustrated that the un intended consequences of PIL can be injurious to public good. Twenty one legal suits in a span of two years from 2014 have been filed against SGR. To determine the adequacy of the rules to mitigate on the un intended consequences, the Constitution of Kenya (Protection of Rights and Fundamental Freedoms) Practice and Procedure Rules 2013 applicable to PIL in Kenya were investigated to determine their adequacy as applied in SGR Cases. These rules of procedure as applied in the SGR case form the basis of this study. A review of these rules has revealed that there is need to amend the rules to include timelines, vetting potential PIL, placing of a bond before filing PIL, punishing petitioner among others in order to mitigate on the un intended consequences of PIL.