The aim of the present study was to determine the prevalence ofDirofilaria immitisin stray, pet, and working dogs (n=413, 266, and 103, resp.) from Guwahati (Assam) and Aizawl (Mizoram), areas located in two Northeastern States of India. Diagnostic methods applied were microscopy (wet film and Knott’s concentration technique), immunological test (Ag ELISA by SNAP 4Dx ELISA kit), and molecular tools (polymerase chain reaction and sequencing), which evidenced 11.38, 18.03, and 13.93% of positive animals, respectively. No significant differences were observed by area (18.23% versus 17.68%) nor by sex (18.1% versus 17.9%), whereas stray dogs proved more infected than other groups (P<0.05). ELISA test evidenced an overall 22.69% of occult infections, mainly in working dogs (60%), and molecular techniques detectedDirofilaria (Nochtiella) repensin 4 stray dogs from Guwahati. Characterization ofD. immitisisolates for ITS-2 region showed close identity with South Asian isolates.