This work focuses on development of a multispectral imaging system for intraoperative diagnosis aid purpose. The system should be able to identify and differentiate biological tissues in an operative scene, by measurement of their spectral reflectance in the visible and the near infrared wavelength range. Multispectral images in the near infrared may be used to see in depth and to identify buried tissues. The paper introduces a multispectral imaging device we have developed and validated by in vitro measurements. In vivo tests need specific measurements protocol and should be carried later. The imaging system is composed by one calibrated CCD camera, by one optical device with three holographic gratings and by halogen light source. Multispectral images produced by this system are obtained according to the 0°/45° CIE standard geometry. In order to validate this system to evaluate measurements fluctuations several tests were made on different muscle slices. This study showed a fluctuation of 20% to 30% on the same slice of a given tissue. This large error rises from the intrinsic, complex and non homogeneous nature of biological tissues. It represents a great limitation to this spectral measurements technique and affects its ability in terms of tissues spectral reflectance factor evaluation.