The effect of different forms of selenium (Se) (selenate, selenite in concentration 10 mg Se/L) and iodine (I) (iodide, iodate in concentration 1000 mg I/L) and all their combinations on selected biochemical, physiological and morphological traits in kohlrabi were studied. We have grown kohlrabi from seeds initially in greenhouse, then we have transplanted them to the field. Between their growth we foliarly sprayed them with control and different solutions of Se, I and their combinations. We measured content of chlorophyll a and b, carotenoids, anthocyanins and UV absorbing compounds, electron transport system (ETS) activity, photochemical efficiency of photosystem (PS) II and optical properties. We also measured the morphology of individual plants. We have found that different forms of Se, I and all their combinations have either different impact on the measured parameters or the impact was not found in kohlrabi plants. Different forms of Se and I had no negative or positive effect on ETS activity, morphological properties and photochemical efficiency of PS II. The epidermis thickness, the content of anthocyanin and the content of UV absorbing compounds of kohlrabi leaves, treated with different forms of Se and I, were in correlation with optical properties of leaves. Different forms of Se and I have different impact on measured parameters in kohlrabi.