The performance of the Swedish education system is monitored via a range of tools including participation in international assessments, aggregation of data from national assessments, thematic quality evaluations by the Inspectorate and evaluation reports by the National Agency for Education. Results of system-level evaluation are taken seriously and feed into policy development for school improvement. It can be questioned, however, whether much of the data collected on student outcomes are appropriate for the purpose of system monitoring. The current reporting of outcomes relies heavily on grades awarded by teachers, but recent studies show that teachers’ grading is uneven. This implies that aggregating test results and student grades as measures of school, municipality and system performance is not appropriate. Options to provide a more reliable system monitoring tool could include setting up external moderation of national tests or introducing a sample monitoring survey. Also, there is room to encourage greater mobilisation of existing data and information in order to optimise the usability of this information by local policy makers and stakeholders.