In Punjab, the influx of migrant labour particularly in agriculture sector started with the green revolution and picked up subsequently. Due to monoculture in the cropping pattern, the state has become largely dependent on migrant labourers for various agricultural operations. The influx of seasonal as well as permanent labour from outside has led to various socio-economic problems in Punjab. In the wake of this, the present study was purposively conducted in the Central Zone of Punjab for the year 2011 to find the causes and impact of labour in-migration in Punjab. A total of 105 respondents belonging to the states of Bihar, Uttar Pradesh, Jharkhand, Madhya Pradesh and Nepal constituted the sample frame. The results have revealed that better income and employment opportunities at the destination place were the major factors responsible for migration. About 64 per cent of the respondents earned less than ` 20000 per annum at their native places and 60 per cent of them had less than 200 days of employment in a year, whereas 23 per cent of the labourers were unemployed at their native place. However, after migration 63 per cent of the migrants could earn from ` 20000 to ` 50000 per annum and 34 per cent earned more than ` 50000 per annum in Punjab, leading to a major share (60% of total income) as remittances sent back to their native places. On the other hand, the flip side of the influx of migrants in the study area increased the drug menace by 37 per cent, social tension by 45 per cent and crime by 43 per cent. The state government should maintain a demographic balance by regulating the migrants and should help in verification of credentials of migrating labourers to Punjab.