Public Interest Litigation (PIL) is litigation that can be filed in any court of law by any person for the protection of ‘public interest’. It has achieved importance in the Indian legal system and is a landmark of judicial activism. It developed through the decisions of Justice V.R. Krishna Iyer, Justice C. J. Chandrachud, and Justice P. N. Bhagawati. Some significant cases include 

• Katara (human rights activist) vs Union of India case that changed the way that public authorities handled medicolegal cases such as in case of road accidents. 
• Vishaka’s judgment provided guidelines with regard to women’s rights and especially sexual harassment (prevention of and dealing with cases of sexual harassment). This judgment came after the Bhanwari Devi rape case and subsequent PIL filed by Naina Kapur, a lawyer. 
• H. Khatoon vs State of Bihar (1979) – This case drew the attention of the court to the pathetic condition of undertrials in Bihar. This tried to ensure speedy trials. 
• Mehta vs Union of India (1988) with regard to pollution of the Ganga basin covering 8 States in India.