Beryllium precipitation from the Cu-rich matrix in a Cu-2 wt% Be alloy homogenized and quenched from 1073 K was studied by differential scanning calorimetry (DSC). The DSC traces showed two main exothermic effects, A and B, each comprising two sub-effects A(1), A(2), and B-1, B-2 respectively. Effects A(1) and A(2) correspond to the precipitation of GP zones and subsequent overlapping and independent precipitation of gamma "-phase. Only at very low heating rates can gamma " be inherited from GP zones. Effects B-1 and B-2 correspond to heat evolved during transitions to the states with gamma’- and gamma-phases respectively. Heat effect A can be quantitatively described in terms of solid solubilities before and after precipitation, and of precipitation heats of the phases involved. The heat content of the combined GP zone/gamma "-phase precipitation effect was proportional to the beryllium atoms precipitated, yielding an average value of 21 kJ mol(-1) beryllium for beryllium precipitation. It was shown that gamma’-phase arises from the combined transition from states with GP zones and gamma "-phases, whereas gamma arises from the transition of states with gamma " and gamma’. The apparent activation energies associated with GP zones, and gamma ", gamma’- and gamma-phases are 0.94 +/- 0.07, 1.26 +/- 0.07, 1.31 +/- 0.08 and 1.69 +/- 0.1 eV respectively. These values are discussed in terms of dissolved atom mobility related to vacancy concentration, and the direction of plate-like precipitate growth (either normal or perpendicular to the plate). Small discontinuous precipitations of gamma-phase occurred along with the transformation to the state with gamma’-phase.