Phosphoprotein phosphatases are central regulatory components of the cell cycle in eukaryotes. We report the cloning and sequencing of an alfalfa phosphoprotein phosphatase type 2A (pp2aMs) cDNA. The predicted protein sequence shows high similarity to PP2A from Brassica napus, rabbit and Drosophila. No changes in pp2aMs mRNA abundance during the cell cycle were found. During growth of a batch cell culture, mRNA levels decreased gradually. In planta, all organs contained pp2a transcripts but maximal mRNA levels were detected in stems. Since Southern analysis indicated the presence of a small pp2a gene family in alfalfa, it appears that different subtypes may have specialized roles in various tissues and developmental situations which await characterization.