The complex crystallization behavior of the Zr40Ti15Cu10Ni10Be25 bulk metallic glass (BMG) produced by suction-casting method was studied with the non-isothermal DSC measurements with the heating rate from 5 to 40 K/min. Three exothermic phenomena were observed for the investigated material. The novel evaluation procedure for qualitative and quantitative analysis of intricate crystallization kinetics for Zr-based BMGs is proposed. The unusual deconvolution of the DSC curves based on a Gaussian function and a two-phase exponential decay function allowed for separate, detailed analysis of overlapped peaks. The activation energies for each crystallization stage were studied based on overall (Kissinger) and local (Kissinger–Akahira–Sunose) procedures. The KAS method applied separately for both low and high heating rates showed a significant difference in local activation energies. Finally, the local Avrami exponent evaluation revealed that the first two stages of crystallization are diffusion-controlled with mainly increasing nucleation rate, whereas the third crystallization is more growth-dominated.