Girth increments of trees were studied using band-dendrometers in some semi-deciduous forests in Lamto (Ivory Coast). Every tree over 20 cm gbh was monitored monthly, during 5 to 9 years, in seven stands. Girth increments' distributions were log-normal in the forest stands studied, a few individuals contributing to the largest part of the forest production. Girth increments vary widely; even between trees of similar size; several types of girth increment were described (regular, intermittent, increasing or decreasing etc.). A yearly periodicity of growth, in conformity with the local climatic cycle, is the pattern most commonly observed, mainly in fast growing trees, but yearly bimodal patterns and dry season increments were also observed. The variability of growth patterns is mainly due to intra-specific variability. At the community level the mortality rate of trees ranges, between stands, from 1 to 4%.