Acute graft-versus-host disease (GVHD) is major cause of morbidity and mortality following hematopoietic stem cell transplantation (HSCT). Main pathogenetic mechanism is immunologic reaction of the graft cells agains the recipient tissues due to histocompatibilty mismatch. The disease most commonly affects skin, gastrointestinal tract and the liver, but the incidence and the severity of the simptoms vary. Despite numerous research, there is still no optimal therapeutic strategy. The aim of this paper was to analyse therapeutic response in patients with acute GVHD. The study included 26 adult patients who developed clinically significant acute GVHD following allogeneic HSCT and their data was analysed retrospectively. The incidence of the acute GVHD was 22,5%.16,3% of the total number of the patients developed grade II or higher GVHD. First-line therapy response was 50% of the patients with clinically significant GVHD. Three (11,5%) patients died during first-line treatment, while others, 38,5% of the total number of the patients, developed steroid-refractory GVHD. Extracorporeal photopheresis (ECP) and ruxolitinib were used for the treatment of the steroid-refractory GVHD. 33,3% of the total number of the patients treated with ECP responded to the therapy. The response rate for the treatment with ruxolitinib was 33,3%, as well. 46,2% of the patients with clinically significant GVHD have died. The most common cause of death, in 50% of the cases, was the progression of the GVHD. Overall survival in the group of the patients who responded to the first-line therapy was 83,0%, while the survival of the patients with the steroid-refractory GVHD was 28,5%. This difference, according to the log-rank test, was statistically significant. (p=0,0031) Given the substantial effect that developing of the steroid-refractory GVHD has on the GVHD mortality, response to the first-line therapy is considered to be the most important predictor of the long-term survival.