The chapter is focussed to brief about protozoal infections, arthropods and parasitic infections. Protozoa are microscopic, one-celled organisms that can be free-living or parasitic in nature. A variety of arthropods, protozoa, and parasites infect the skin and subcutaneous tissues. Scabies is transmitted by intimate personal contact, sharing of inanimate objects, and fomite. Burrow is the pathognomonic lesion of scabies. KOH or mineral oil mount of scrapings demonstrate the mites, eggs, fecal pellets (scybala). Fountain pen ink when applied on burrows will remain inside the burrow and make them more visible. Wood’s lamp also helps in the diagnosis of scabies. Five percent permethrin and oral ivermectin are used as treatment of scabies. Pediculosis, insect bite hypersensitivity, leishmaniasis (kala-azar), cutaneous larva migrans, erythema chronicum migrans, etc. are also covered in the chapter.