As part of a tick-borne disease surveillance program, ticks were collected using tick drags and by making incidental collections from humans and animals in six provinces (Gyeonggi, Gangwon, Chungnam, Gyeongbuk, Gyeongnam, and Jeonbuk) of the Republic of Korea (ROK) during 2020–2021. A total of 57,751 Haemaphysalis longicornis, 2,020 H. flava, 1,861 Ixodes nipponensis, 14 H. phasiana, 9 H. japonica, and 9 Amblyomma testudinarium were collected. Cases of ectromely were observed in two H. longicornis with six legs (one female and one nymph), and six H. longicornis (two females and four nymphs), two female Haemaphysalis flava and one male Ixodes nipponensis with seven legs. Additionally, two female H. longicornis were found with extra legs (tarsus), and two female H. longicornis and one male H. japonica were observed with atrophied legs.