Annular tautomerism (OH center dot center dot center dot N and/or NH center dot center dot center dot O) of hydroxychromenopyrazoles was studied by NMR-spectroscopy and B3LYP/6-311++G(d,p) theoretical calculations. The experimental chemical shifts of 4,4-dimethyl-7-pentyl-2,4-dihydrochromeno[4,3-c]pyrazol-9-ol have been compared with absolute shieldings calculations performed using the GIAO approximation. This study shows that the title compound exists mainly as an OH center dot center dot center dot N tautomer in solution.