The level of delayed skin hypersensitivity (DSH) was evaluated in vivo after dinitrofluorobenzene induction (3rd and 7th week of the experimental) while the level of phagocytic activity (FA) of blood leucocytes (in weekly intervals during six weeks of observation) was evaluated in calves (4.5 to 5.5 months of age) after administration of particular fungal glucane (from oyster mushroom) at a dose of 10 mg/kg live weight. In calves which were administered glucane (abbr. G), a significantly stronger cell-mediated immune response was recorded by means of DSH test in the 3rd week of observation, namely in comparison with its starting value (P < 0.01) and also with the value of control animals (P < 0.01; K group)-Tab. I. In the seventh week of the experiment there was not a statistical difference in the average values of DSH any more (Tab. I). But at that time 100 percent of calves showed a skin reaction above 6.5 mm (mean = 7.64 +/- 0.55) evoked by the used sensibilizer in the G group; this reaction was significantly higher (P < 0.01) in comparison with the value of DSH in a majority (80%) of calves of the K group (mean = 6.15 +/- 0.21)-Fig.1. The immunostimulating effect of the used glucane on the FA of blood leucocytes was less significant.(ABSTRACT TRUNCATED AT 250 WORDS)