Two field experiments were established on nutrient poor, sandy soils in Klosterheden National Forest and in Mangehoje Forest Plantation in western Denmark to quantify the effect on site productivity of whole-tree harvesting in early thinnings of Norway spruce, The growth response following biomass removal was investigated for four treatments: (1) no thinning (NT), (2) whole-tree harvesting in which the felled trees were removed immediately after thinning (WTHgreen), (3) whole-tree harvesting in which the felled trees were left to dry in the stand during the following growing season so that some of the nutrient rich parts of the tree such as needles and twigs are returned to the forest floor (WTHdry), and (4) harvesting of stems and coarse branches with needles and twigs being threshed from the branches and left in the stand (SCB). The results indicated that WTHgreen might lead to a short-term reduction in stand volume increment of the remaining stand. Comparing the mean annual increment during the first four growing seasons after treatment, using the initial standing volume as a covariate, WTHgreen caused a significant growth reduction of 10-18% at Klosterheden and 5-17% at Mangehoje, compared to the SCB- and WTHdry-treatments. The effect of WTHgreen was attributed to an increased removal of essential nutrients such as N, P and K. The growth response following whole-tree harvesting was confined to the first four growing seasons and the effect of different treatments was not significant when data for all ten growing seasons were analysed.