Anther development requires the coordinated differentiation of several cell types. Recent molecular genetic analyses have led to exciting advances in our understanding of anther cell division and differentiation. The SPOROCYTELESS/NOZZLE (SPL/NZZ) gene is a putative transcription factor critical for early anther cell division and/or differentiation. Several genes that regulate tapetum formation and differentiation have been isolated, including EXCESS MICROSPOROCYTES1/EXTRA SPOROGENOUS CELLS (EMS1/EXS), SOMATIC EMBRYOGENESIS1(SERK1), SERK2, and TAPETUM DETERMINANT1 (TPD1). Also, genes important for normal tapetum differentiation and function have been uncovered, including two closely related MYB genes, MYB33 and MYB65, which are post-transcriptionally regulated by microRNAs, and the rice Udt1 gene. Finally, genes encoding putative transcription regulators, ABORTED MICROSPORES (AMS) and MALE STERILITY1 (MS1), and a lipid metabolism enzyme, AtGPAT1 are important for pollen development. These discoveries have ushered in a new era for understanding the control of cell division and differentiation during plant male reproductive development.