Formative assessment, including vocational education and training (VET), has been included in the assessment regulations in Norway since 2006. This study examines how a continuing education course entitled Assessment for learning in vocational education (15 credits) might contribute to vocational teachers' professional development related to assessment for learning. Qualitative data was collected in two stages from vocational teachers participating on the course. The findings reveal that perceptions of assessment for learning and vocational formative assessment practice are developed through the lens of the general study programmes and are dominated by academic subjects in upper secondary schools. However, assessment for learning is embedded in vocational learning and teaching and needs to be voiced in the educational discourse in schools related to formative assessment. Vocational teachers' professional development in assessment for learning should be based on the characteristics and attributes of vocational learning.