We determined fine root biomass and production of 15-, 35- and 100-year-old Scots pine (Pinus sylvestris L.) stands during three growing seasons. Fine roots were sampled by the soil core method. Mean (± SE) annual fine root biomass of Scots pine in the 15-, 35- and 100-year-old stands was 220 ± 25, 357 ± 21 and 259 ± 26 g m−2, respectively. Fine root biomass of the understory vegetation was 159 ± 54 g m−2, 244 ± 30 and 408 ± 81 g m−2, and fine root necromass was 500 ± 112, 1047 ± 452 and 1895 ± 607 g m−2 in the sapling, pole stage and mature stands, respectively. Both understory and Scots pine fine root production increased with stand age. Mean annual Scots pine fine root production was 165 ± 131, 775 ± 339 and 860 ± 348 g m−2 year−1 in the sapling, pole stage and mature stand, respectively. The respective mean annual production of all fine roots (Scots pine and understory) was 181 ± 129, 1039 ± 497 and 1360 ± 869 g m−2 year−1. The Scots pine and understory fine root biomass, necromass and production varied in relation to stand age, although the variation was not statistically significant.