There has been almost a consensus among the political opinion makers in India that the Constitution of India that came into force in 1950 has been a secular constitution. This paper critiques that consensus and demonstrates that the secularism of India's constitution is Hindu-tainted. It takes up some key articles of the Indian constitution and, by analysing the constitutional debates of the 1940s that went into the making of those articles, highlights the Hindu bias features of the Indian nationalist movement and the constitution. While acknowledging some admirable and progressive features of the constitution, the paper argues that its Hindu bias must be read as symptomatic of the depth of institutionalised Hindu communalism in India and the shallowness of the secular foundations of the Indian republic. The existence of institutionalised Hindu communalism means that the power of Hindu communal sectarianism is greater than that which is merely represented by Hindu nationalist organisations. The paper concludes by suggesting that the secular reconstruction of India demands critical combat with the institutionalised communalism embedded in a range of societal and state institutions. Examining Hindu bias in the constitution is an instance of an examination of institutionalised communalism in one key institution of the Indian state and society.