Purpose: In this work was presented the cooling rate influence on microstructure of the Zn-Al cast alloy. This research work presents also the investigation results of derivative thermoanalysis performed using the UMSA device. The material used for investigation was the ZnAl4Cu1 alloy. Design/methodology/approach: Moreover the analysis of cooling rate influence on the derivative curve changes was performed as a result of the measured crystallisation kinetic changes. For the assessment of the cooling rate influence on the mechanical properties also hardness measurements were performed using the Rockwell hardness device. Findings: The treated sample is without holes, cracks and defects as well as has a slightly higher hardness value compared to the as-cast material. Research limitations/implications: The material was examined metallographically and analyzed qualitatively using light and scanning electron microscope as well as the area mapping and point-wise EDS microanalysis. The performed investigation are discussed for the reason of an possible improvement of thermal and structural properties of the alloy. Practical implications: The investigated material can find its use in the foundry industry; an improvement of component quality depends mainly on better control over the production parameters. Originality/value: This work provides better understanding of the thermal characteristics and processes occurred in the new developed alloy. The achieved results can be used for liquid metal processing in science and industry and obtaining of a required alloy microstructure and properties influenced by a proper production conditions. Reference to this paper should be given in the following way: B. Krupińska, L.A. Dobrzański, Z.M. Rdzawski, K. Labisz, Cooling rate influence on microstructure of the Zn-Al cast alloy, Archives of Materials Science and Engineering 43/1 (2010) 13-20.