Tetraploids were induced in Spathiphyllum wallisii Regel (2n=2x=30) through in vitro application of mitosis inhibitors. Tetraploids were compared to the original diploid control plants. Polyploidization had a significant effect on plant anatomy and morphology. The stomatal area of diploids was smaller compared to the tetraploid plants. The leaf angle was smaller in diploids. The stomatal length and width, leaf thickness and angle and thickness of the spathum were positively correlated to the higher ploidy level. On the other hand, stomatal density, length/width ratio of leaf, spathum and spadix, number of shoots and leafs and length of the flower stalk decreased in tetraploids compared to the corresponding diploid controls. The leaf number of diploid plants was higher compared to tetraploids. Altogether, this study quantified the extended morphological changes of chromosome doubling in our model crop Spathiphyllum wallisii.