Most of the CO I lines recorded by high-resolution Fourier transform spectrometry in the region 3000-45000 cm-1 (30000-2222 Å) show significant hyperfine structure. Computer fits to 1020 of these line profiles have yielded values of the magnetic dipole hyperfine interaction constant A for 297 energy levels with an uncertainty of between 0.2% and 3%. The A factors range from -0.0236 to +0.0598 cm-1 for the even levels, and from -0.03387 to +0.1028 for the odd levels. For 208 of these A factors no previous measurements are known. Approximate values of the electric quadrupole hyperfine interaction constant B were found for 156 levels. These measurements of A and B factors allow, for the first time, correct allowance to be made for the effects of hyperfine structure in CO I both for abundance analysis and in the resolution of blended lines.