The present study was conducted during the 2019/2020 and 2020/2021 growing seasons at Shandaweel agricultural research station, Sohag governorate to study the individual and combined effect of three rates of rice straw biochar and four rates of N, P and K mineral fertilizers on the agronomic traits, nutrient contents in leaves and grains, protein and carbohydrates content in grains of wheat cultivar Misr 3 as well as on some soil properties. The experiment design was a split plot with three replications, whereby biochar treatments occupied the main plots at a rate of 0, 5 and 10 t ha^-1, while the sub plots were devoted to mineral N, P and K fertilizers at a rate of 0, 50, 75 and 100% of the recommended dose. Results revealed that the combined application of 10 t ha^-1 biochar and 100% N, P and K fertilizers treatment recorded the highest values for all the studied traits as well as improving the soil properties compared to other treatments. Furthermore, the addition of 10 t ha^-1 biochar with 75% and 100% of N, P, and K fertilizers significantly improved grain yield by (11.13 and 18.80%) in the first season and by (7.69 and 16.62%) in the second season, respectively compared to the application of 100% of N, P and K fertilizers without biochar. In conclusion, biochar can be used to reduce using all chemical fertilizers (N, P, and K) by 25% as well as enhancing soil fertility and wheat productivity.