A key lever for improving teaching is provision of effective professional development. This paper uses TALIS 2013 data to consider personal and school-level factors associated with teacher participation in effective professional development and reports of impact on instruction. Results of the analyses indicate that levels of teacher co-operation and instructionally-focused leadership in schools are associated with higher levels of effective professional development participation and reported instructional impact. Systems also vary significantly on the percentage of teachers in schools with supportive conditions and this is associated with differences in teacher participation in professional development types and reported instructional impact.