Documentation of myrmecophily in Lycaenidae butterflies of the Western Ghats in Kerala state, Peninsular India is attempted. Of the 94 lycaenid species hitherto recorded to occur in Kerala, we reared 67 species. Based on larval rearing and literature review, we found that 55.3% of lycaenids in the state were myrmecophilous, 19.1% were myrmecoxenous, and 25.5% were data deficient. Eight species of lycaenids, previously unrecorded as myrmecophilous, were confirmed to be myrmecophilous, and seven species of ants were newly detected to be lycaenophilous. Twenty-two interactions had a hitherto unrecorded ant genus, and 42 involved an unre-ported ant species. A little less than one-fifth of the studied unique interactions were obligatory. Obligatory interaction was highest in the lycaenid Cigaritis Donzel, 1847, followed by Anthene Doubleday, 1847, Arhopala Boisduval, 1832, Catapaecilma Butler, 1879, and Zesius Hübner, 1819. Amongst butterflies, the highest number of ant associations was observed for Jamides celeno celeno (Cramer, [1775]) and Thaduka multicaudata kanara Evans, 1925. Native ants dominated the interactions (77.1% vs. 22.9%). Amongst the ants, Crematogaster Lund, 1831, dominated the unique interactions followed by Anoplolepis Santschi, 1914 and Camponotus Mayr, 1861. Invasive ants attending butterflies strictly endemic to the Western Ghats were not observed. ARTICLE HISTORY