Ecological survey of weeds associated with garlic crop in Karnal, Ambala, Yamuna Nagar and Kurukshetra districts in north-eastern zone and Bhiwani and Hisar in south-western zone of Haryana state was conducted during two consecutive years in rabi 2006 and 2007. Among 17 known species spotted in garlic fields, 4 were grassy, 12 broad leaf weeds and only one sedge was recorded. Cyperus rotundus. Anagallis arvensis, Chenopodium album, Melilotus indica, Coronopus didymus, Medicago denticulata and Spergula arvensis among broad leaf weeds and Phalaris minor, Poa annua and Polypogon monspliensis among grasses were the major weeds of garlic in all districts. In Karnal, Ambala and Hisar, Anagallis arvensis was the most dominant weed with a relative density (RD) of 18.1, 16.1 and 16.4%, respectively with 100% occurrence in all the three districts while in Kurukshetra, Poa annua dominated weed flora with 20.5% of total weed flora followed by P. minor, A. arvensis and C. album in Yamuna Nagar district. P. minor was the most dominant weed with RD of 19.6% where as in Bhiwani, Chenopodium murale was the most dominant weed of garlic. Trigonella polycerata a weed of light textured soils was found in loamy sand soils of Bhiwani district only.