This study employed a randomized experiment to examine differences in teacher and student learning from professional development (PD) in two modalities: online and face-to-face. The study explores whether there are differences in teacher knowledge and beliefs, teacher classroom practice, and student learning outcomes related to PD modality. Comparison of classroom practice and student learning outcomes, normally difficult to establish in PD research, is facilitated by the use of a common set of curriculum materials as the content for PD and subsequent teaching. Findings indicate that teachers and students exhibited significant gains in both conditions, and that there was no significant difference between conditions. We discuss implications for the delivery of teacher professional learning.