Leaf morphology is highly responsive to environmental conditions and plays an important role in plant adaptation along climatic gradients. However, anatomical variation in needle sclerenchyma cells has rarely been examined across populations of Cedrus atlantica. This study, investigates variations in the sclerenchyma cells of needles across three Moroccan Middle Atlas cedar populations: two populations from Kha and Mou in Azrou region, and one population from Tam in Ifrane region, at an altitude of between 1,605 and 1,823 meters. Several sclerenchyma cell traits in needle cross-sections were measured: Number and area of sclerenchyma cells at the hypoderm the endoderm and surrounding the resin canal; number of sclerenchyma cell : the type with thick walls and restricted lumen, type with intermediate character and cell type with thin wall and wide lumen in the endoderm and in the surrounding resin canal, and their variation among populations was analysed using a light numeric microscope (Optika DM-15) with ten trees of each population and ten needles per tree. Descriptive statistics, a Student’s t-test, discrimination power, and a dendrogram based on the closest Euclidean distances were calculated for the traits. The descriptive statistics revealed variation in the area of hypodermal sclerenchyma cells, which varies among populations. A Student’s t-test of the mean percentage of the different types of sclerenchymatic cells in the endodermis and surrounding the resin canals revealed significant differences between the analysed cedar populations. In contrast, agglomeration of populations over short Euclidean distances revealed the sclerenchyma cell traits consistently separated two major population groups corresponding to cold subhumid and fresh humid climatic conditions (Climate-Data.org.). Analysis of the discrimination power revealed a high level of distinction between the studied populations of C. atlantica for four of the twelve analysed needle traits. These results suggest that needle sclerenchyma traits reflect ecological differentiation associated with temperature (T= 11.3 °C for Tam and 14.2 °C for Kha and Mou) and precipitation (P= 843 mm for Tam and 779 mm for Kha and Mou) regimes. These traits may provide useful anatomical markers for studying and conserving Cedrus atlantica at a population level in Morocco.