Understanding teachers’ conceptions of assessment is a key objective in supporting assessment practices that lead to improved learning outcomes. Thus, inventories capable of identifying teachers’ assessment conceptions are important. The Teachers Conceptions of Assessment (TCoA) inventory was an early and influential measure of teacher assessment conceptions, but replication studies have shown that the model may be affected by policy and practice context. In the present study, a Swedish adaptation of the TCoA was administered twice, 18 months apart. A sample of 249 teachers were matched across the 2 time-points and their self-reported scores were analysed with confirmatory factor analysis and invariance testing. With good correspondence to the data, six of the nine factors in the TCoA were completely replicated and one factor was partially replicated. The model had sufficient similarity between time points to permit mean score comparisons, which were largely equivalent between times. The study indicates that the Swedish Teacher Conceptions of Assessment adaptation can be used reliably in Swedish primary and lower secondary schools as measure of teacher conceptions of the uses of assessment.