This graduation thesis deals with the health of woody plants in Spa park in Rimske Toplice. Assessment of the species composition/harmfulness of insects and mites and species compostion/pathogenicity of fungi that were found in central part of the park was made. Analasys took place during vegetation growing season in July and August 2013. In this time samples of plant parts showing symptoms were collected. 34 different species were determined, of which there were 21 insects, 8 pathogenic fungi and 5 mites. This organisms mainly impact aesthetic value of their host plants. Horse chestnut leaf miner (Cameraria ohridella) and Guignardia leaf blotch (Guignardia aesculi) have heavily impacted vitality of horse chestnut (Aesculus hippocastanum). Vitality of giant sequoias (Sequoiadendron giganteum) is severly impacted by Botryosphaeria canker and dieback caused by Botryosphaeria dothidea. Damage levels to most important tree species in park, namely A. hippocastanum, P. % hispanica, S. giganteum, were assesed. Aditionally instructions on how to improve vitality of esthetically and ecologically important woody plants that grow in the park were given.