This experiment was carried out to investigate the effect of harvesting frequency on yield and nutritive value of cassava foliage. It was arranged in a Randomized complete block design (RCBD). Two treatments were two different ages of cassava foliage of initial harvesting, at 2 and 4 months; (IC2) and (IC4). The subsequent harvestings for both were at every 2 months until the cassava foliage was 8 months old. Cassava Rayong 5 (RY5) was cultivated as a monoculture for all plots; each plot was 5x10 m (50 m2), and 150 kg/ha of commercial fertilizer (46-0-0, N-P-K) was applied to cassava crop at the start. The results showed that cassava foliage yield was significantly different (P<0.05) among harvesting times within the treatments. For the initial harvesting at (IC2), dry matter (DM) yield was highest in the second harvest (H2) and was lowest in the fourth harvest (H4) (3.2 and 1.2 tonnes/ha, respectively). For the treatment of initial harvesting at (IC4), DM yield was greatest in the first harvest (H1) (3.3 tonnes/ha) and was lowest in the third harvest (H3) (1.2 tonnes/ha). The foliage yield at each harvesting time significantly decreased (p<0.05) with the crop age. However, total DM yield was not significantly different among treatments. Total DM yields of IC2 and IC4 were 7.1 and 6.5 tonnes/ha, respectively. The fiber contents, NDF, ADF and ADL, were significantly (p<0.05) higher in IC4 than IC2, especially in the first harvest (H1) (56.4, 37.5 and 14.6%, respectively). In contrast, CP was significantly higher in IC2 and up to (21.5%).