Sixteen full sib families of Norway spruce(Picea abiesL. Karst.) were measured for height, diameter and wood density (pilodyne method) in a 13‐year‐old field trial located in Jutland/Denmark. Left‐over seed of the same families was resown and after three years tested for growth (height and dry matter production), gas exchange (photosynthesis, respiration and transpiration) and winter frost resistance under controlled conditions. Significant differences between families were obtained in all traits except photosynthesis. No correlation, however, could be found between seedling growth (3 years) and field performance (13 years). Highly significant correlations were obtained between field growth and transpiration on one hand, and water use efficiency of the seedlings on the other (increased growth with decreasing transpiration on one hand, and increasing water use efficiency on the other). Winter frost resistance was significantly correlated to field growth (increasing growth with increasing frost hardiness). By means of water use efficiency and frost resistance, 48% of the variance in field height, 77% in field diameter and 70 % of the variance between families in volume production could be explained. These narrow correlations pinpoint the possibilities in using physiological parameters for early testing and selection in tree breeeding programmes.