A total of 2809 ixodid ticks were collected by screening 4560 household cattle from six different agro-climatic zones of Tamil Nadu, a southern state of India. Among the ixodid ticks, Rhipicephalus microplus tick isolates were subjected to Adult Immersion Test (AIT) and Larval Packet Test (LPT) using deltamethrin. The mean % of ixodid tick infested cattle population was 63.2%±10.9. Positive correlation was found between the tick burden on household cattle and Resistance Factor (R=0.66). Further, 44% variance in the tick burden on cattle is explained by LPT based resistance factor suggesting deltamethrin resistance level is one of the contributing factors to the tick load on cattle. Analysis of DNA sequence of sodium channel gene domain II-S4-5 linker region of all deltamethrin resistant R. microplus tick isolates, confirmed the absence of point mutation at the 190^th nucleotide which suggests the possible mutation in other regions of sodium channel gene of R. microplus tick isolates of south India and/or alternate resistance mechanisms.