By using multiple (independent) molecular dynamics (MD) trajectories (about 500 ns in total) of photolized carbon monoxide (CO) within solvated myoglobin, a quantitative description of CO migration and corresponding kinetics is obtained. MD results combined with previously reported quantum mechanical calculations on the CO-heme binding-unbinding reaction step in myoglobin allowed construction of a detailed quantitative model, shedding light oil the kinetic mechanism and relevant steps of CO migration and geminate binding. Finally, the obtained (unbiased) theoretical-computational model is critically compared with the available computational and experimental data for myoglobin in Solution.