This study documents the impact of migration, environment and caste on the blood pressure of Sikhs living in the UK and their peers in the native Punjab state of India. A sample of 449 adult Sikhs, males and females, were studied in the Punjab state, and in Southall, in the Ealing borough of London and Handsworth in Birmingham in the UK. There is minor variation in the blood pressure of members of various castes among the Sikhs living in the Punjab. The pattern in blood pressure broadly corresponds with the economic status of the individuals, with well-off groups showing higher blood pressure compared to the poorer groups. The blood pressure of migrants, though higher than that of their sedente peers, is not significantly so. Age at arrival in the UK and the length of exposure to the new environment were generally not significantly related to variation in blood pressure. There seems to be a secular shift in the blood pressure values of the native Punjabi Sikhs compared to earlier studies, possibly because of the rise in civic disturbances and social unrest in the Punjab during recent years.