The chlorophyll content of tobacco is determined by a reflectance measurement on powder and is given by a green index . Initially, the determination of the green index was made on powder finely ground at 15% water content and compacted in a pellet. An adaptation of this method is proposed. In this work, we assess the type of grinding and the water content effects on the green index. As it does not lead to the highest green index, the powder preparation with a ball grinder at 6/7% moisture gives the best humidity stability, the finest and most regular granulation and the best accuracy for the green index. However, the green index determination can be made on other types of powders, with a greater moisture and/or a coarser granulation, then corrected to give the green index under the above conditions. A quartz cell where the powder is compressed by hand leads to the same results as the pellet and provides a simpler and time saving operating mode.