Haemorrhagic fever with renal syndrome (HFRS) is a viral infectious disease of humans that is widespread worldwide and also occurs repeatedly in Croatia. This disease can cause severe clinical forms, sometimes with a fatal outcome, and according to its epidemiological characteristics, it is a natural focal disease that is maintained in a specific area, with rodents serving as a reservoir. Surveillance of HVBS is not carried out systematically in Croatia, except by confirming the disease in humans. Due to the public health importance of the disease, different surveilance systems for monitoring the spread of the pathogen by rodents and, to a very limited extent, by various sentinel animals have been researched worldwide. In this study, 120 cats from free-range, semi-free-range or stray cats from endemic HVBS areas in Croatia were tested for the presence of orthohantaviruses antibodies using a commercially available enzyme-linked immunosorbent assay (ELISA). When performing the ELISA method, a modification was made using secondary antibodies labelled with horseradish peroxidase for cat IgG antibodies to adapt the method for cat sera.All tested animals were serologically negative, which is surprising considering the epidemiological situation for HVBS in this part of Croatia. This could be a consequence of research limitations due to a relatively small number of samples tested and a short study period, incomplete anamnestic data and the lack of an officially validated method. Although this first study on cats as potential sentinel animals in Croatia has not confirmed the possibility of using these animals as sentinel animals for HVBS, it is necessary to continue and expand the investigation that has been started. Elimination of the identified shortcomings is necessary to reliably investigate the possibility of introducing a surveillance system for this important zoonosis by testing cats or other domestic animals in accordance with the One Health approach.