This paper analyses the effects of soil and foliar fertilization with sodium selenate (VI) on the selenium content in spring wheat grain. The research was carried out at the Departmental Experimental Station of the Institute of Agriculture WULS in Skierniewice in 2018 and 2019. The dose of selenium used was 5.00 g Se·ha−1 in various development stages of spring wheat. The results showed that selenium fertilisation did not affect the size of the grain yield, but both soil and foliar fertilisation significantly increased the content of selenium in wheat grain compared to the control group. The highest Se content was obtained with the method of soil fertilisation combined with the foliar application with a total dose of 10.00 g·ha-1 Se in the stem elongation phase (S + F2), and in the tillering and stem elongation phase (S + F1 + F2), which resulted in the values of 0.615 and 0.719 mg·kg−1 Se in grain, respectively. On this basis, it was concluded that the best time to carry out foliar fertilisation treatment is in the stem elongation phase (BBCH 30–39). The results show that the greatest increase in selenium content in the grain is achieved with soil and foliar fertilisation combined.