A skin reflectance spectrophotometer was constructed for determination of colour changes in dermatological disorders. Objective quantification of human skin colour in vivo can be achieved with this apparatus. The spectrophotometer is of simple construction, and it has improved reproducibility compared to previously described instruments. Reproducibility is better than 1.7%, measured in comparison to a standard white 100% reflecting surface. Due to 1) the short scan time of 20 s, 2) small and mobile measuring head, and 3) the use of optical fibers for delivering and detecting light, the apparatus is suited for clinical spectral colour measurements and comparison of different treatment effects in most anatomical regions. By use of computer technology, it is possible to make fast and reliable comparisons of spectrograms, and to perform chromophore analysis from the recorded data.