Throughout most of its range it occurs in moist lowland and montane forests (primary and secondary), forest-savanna mosaics, gallery forests, thickets and isolated forest patches within moist savanna woodlands; also present in plantations and farm bush; in montane areas it occupies bamboo thickets and steep wooded slopes (East 1999, Kingdon and Lahm 2013). In Angola recorded in miombo woodland (P. Vaz Pinto pers comm. December 2015).

The Yellow-backed Duiker has the widest distribution of the forest duikers, ranging from south-western Senegal through West Africa to south-western South Sudan and south-west Uganda, east to the Albertine Rift and south to north-central Angola and Zambia; they also occur in the Mau forest in south-west Kenya (Kingdon and Lahm 2013). They are now considered extinct in The Gambia (East 1999), although whether they actually ever formerly occurred is uncertain (Grubb et al. 1998). They were thought to have been extirpated from Rwanda (East 1999), but have been confirmed as surviving in the Nyungwe Forest (F. Mulindahabi and A. Vedder pers. comm. in Kingdon and Lahm 2013). Now considered rare in Senegal, Guinea, Sierra Leone, Nigeria, Kenya and Uganda and over much of the periphery of the range (Kingdon and Lahm 2013, and references therein).

Recent presence in Chad is unconfirmed (Kingdon and Lahm 2013) and in Uganda the only confirmed site is Bwindi Impenetrable Forest (East 1999).

About one-third of this estimated population occurs within protected areas: Ziama and Diécké (Guinea); Gola Forest (Sierra Leone); Mbam Djerem, Lobéké (Cameroon); sevral national parks in Gabon; Odzala and Nouabalé-Ndoki (Republic of Congo), Monte Alén N.P. (Equatorial Guinea), Bwindi Impenetrable and Queen Elizabeth NPs (Uganda) Kafue and Kasanka NPs (Zambia); Okapi Faunal Reserve (DR Congo) (East 1999, Kingdon and Lahm 2013).

Listed on CITES Appendix II.