Nowadays, zeolites are being used more and more in various fields of industry. Conclusions from numerous studies indicate their favourable properties for use in construction and architecture. The aim of the article is to provide a description of zeolites` influence on the properties of cement composites and to present the author’s own test results. The tests were conducted on mortar with the addition of zeolite in the amount of 10% cement weight, and determined the flexural and compressive strength, after 3,7 and 28 days of curing. Some fractographic research was also conducted on the obtained results from the flexural strength test, and surface breakthroughs.