The High Niger National Park is one of the most important protected areas for biodiversity conservation in Guinea. This study examined the temporal evolution of the bushmeat trade in three rural markets in the Park and in the nearest urban centre, Faranah. We collected data in markets during August–November 2017 in three villages around the Mafou core area of the Park and in Faranah, and compared these data with equivalent published data from the same rural areas in 2001 and 2011 and from Faranah in 1994, 1995, 1996 and 2011. Across all study periods, mammals predominated in the bushmeat trade. In rural markets we noted a marked increase in the number of carcasses and biomass offered for sale from 2001 onwards, whereas in Faranah there were no differences over time other than a peak in 1996. Overall, there was an increase in the sale of smaller sized species (< 10 kg), and a marked increase in the sale of species that forage on crops, including the green monkey Chlorocebus sabaeus and warthog Phacochoerus africanus, in spite of religious taboos against the consumption of primates and Suidae. Green monkeys were not sold in markets during the 1990s but were the dominant species in Faranah in 2011 and 2017. Our findings suggest a marked shift in traded species, associated with crop protection by farmers and economic incentives to kill and trade crop-foraging species. This study highlights the value of a longitudinal perspective for investigating the dynamic relationship between local livelihoods and biodiversity conservation.