This paper analyses NSS data to understand the trends and dimensions of casualisation of the workforce in all-India and 15 major states during a period covering the past twenty years. The specific questions addressed are: What has been the trend of casualisation of the workforce at the all-India level during the period 1983 to 2002? Is there any trend-break as regards casualisation of the workforce, particularly in the post-liberalisation period? What has been the degree of casualisation of the workforce across various states of India? What explains the inter-state variations in the casualisation of workers?.