Thesis discusses methods for determining fire resistance of cross-laminated timber elements. Two different methods are presented, one according to EN 1995-1-2 and one according to CLT Handbook. Procedures of numerical modelling of cross-laminated elements are presented as well. Based on reports of experimental analyses, where some of them were made in real scale, comments, corrections and findings are offered. It appears that when determining fire resistance according to standard EN 1995-1-2, zero-strength layer d0 and charring depth dchar are most questionable. Indirect difficulty with crosslaminated elements is delamination phenomenon, and with latter connected numerical modelling and integration of phenomenon in current calculation methods, that are still relatively inaccurate. Specific problem is the determination of the critical temperature at which the glue separates and therefore lamination occurs as well as determination of higher degree of charred wood that occurs due to delamination. The last chapter presents the essential part of the thesis. In this chapter, parametric study for determining fire resistances of CLT slab according to European EN 1995-1-2 and Canadian CLT Handbook is performed. Parametric study discusses the effects of different sizes of openings and size of fire compartment where development of parametric fire is determined according to EN 1991-1-2. It was found out that fire limited to solely one room does not cause failure of the CLT slab, but in the case if fire progresses to entire apartment, fire would cause failure of the CLT element. Last part of the parametric study discusses deviation between both methods for determining the standard fire resistance of CLT elements. In the study influence of varying number of layers and length of CLT plate is compared. Comparison showed that more conservative results are obtained with CLT Handbook method.