The binding energy of hydrogen atoms to a (10,0) single-walled boron nitride nanotube (SWBNNT) is calculated at 25%, 50%, 75%, and 100% coverage using the density functional theory. The average binding energy is highest at 50% coverage when the H atoms are adsorbed on the adjacent B and N atoms along the tube axis and the value is -53.93 kcal/mol, which is similar to half of the H - H binding energy. Also, the band gap (-4.29 eV) of the pristine (10,0) SWBNNT is decreased up to -2.01 eV for the H-adsorbed BNNT with 50% coverage.