The change in area of mangrove forests since 1958 in Maputo Bay, Mozambique was studied. Around Maputo, a 44␛eduction of the area was linked to differences in accessibility, the areas closest to Maputo suffering most. But surprisingly, large expansions of mangrove forest were also observed. This increase in area ( 13€was accompanied by an increase in tree cover from 55 to 70ÐThe overall effect of mangrove forest reduction and growth resulted in a mean decrease of only 8ÐThe causes of the increase in mangrove area on Inhaca island are discussed, and two possible factors are suggested: a change in sedimentation and an increase in temperature. Sandbanks have increased at Inhaca Island, but no data are available for the other areas. An increase in sea and air temperature has also been noted by other authors and could explain the growth of the forests, which are situated at the southernmost limit of their normal distribution.