Complement fixation test reactions to the following viruses were studied in 372 samples (157 rodents, 172 domestic animals, 43 persons) from Pakistan: Bunyaviridae, Phlebovirus: Phlebotomus fever Sicilian (PFS), Phlebotomus fever Naples (PFN), Karimabad (KAR), Salehabad (SAL); Nairovirus: Crimean-Congo haemorrhagic fever (CCHF), Hazara (HAZ), Dera Ghazi Khan (DGK), Dhori (DHO); Uukuvirus: Manawa (MWA); “possible members”: Bakau (BAK), Bhanja (BHA). Reoviridae, Orbivirus: Wad Medani (WM). Unclassified: Wanowrie (WAN). Four of these viruses are Phlebotomus-borne (PFS, PFN, KAR, SAL). The other nine are tick-borne. Antibodies against each virus were detected in sera from rodents. Antibodies against PFS, PFN, KAR, CCHF, DGK, BHA, WM and WAN viruses were detected in sera from domestic animals. Antibodies against PFS, CCHF, DGK, DHO, MWA, BHA, and BHA and WAN viruses were detected in human sera. The presence in Pakistan of KAR, DHO, BHA, and WAN viruses is documented for the first time. Over-all prevalence rates were highest for BHA (12·1%) and WM (10·7%) viruses, followed by DGK, CCHF, PFN and PFS (4·0 to 5·4%) and DHO, KAR, WAN, SAL, MWA, BAK and HAZ (0·3 to 2·1%). Epidemiological factors relating to virus circulation and human disease are discussed.