Strategic environmental assessment (SEA) aims to provide a sound theoretical basis on which to plan for biodiversity and ecosystem services (ES). With the multi-purpose and increasing use of SEA worldwide, it is timely to evaluate the effectiveness of SEA practice in integrating biodiversity and ES considerations. Here, we derive criteria from the International Best Practice Principles on Biodiversity and Ecosystem Services in Impact Assessment to evaluate six Australian SEAs conducted for urban development plans. We use qualitative and quantitative content analysis to examine the endorsed SEA reports. We identify and analyse text references related to the evaluation criteria and use word counting of keywords to supplement and cross-check the validity of our findings. Four significant results emerge from our analysis. First, while goals to achieve no net loss (NNL) or net gain outcomes for biodiversity are mentioned in all case studies, their poor specification may limit their effectiveness. Second, there is limited integration of ES considerations into the SEA reports, limiting the potential advantages that such an approach could provide. Third, offsetting is the most documented type of mitigation measure, potentially signalling a lack of evidence in implementing early steps of the mitigation hierarchy, including avoidance. This could be explained by the low level of integration of biodiversity and ES considerations from the early stages in the planning process, where there is more flexibility to apply such steps. Fourth, biodiversity management systems and follow-up activities lack detailed information to judge whether they will be useful to demonstrate NNL outcomes. Based on these findings, we present recommendations for enhancing the integration of biodiversity and ES considerations in SEAs. Our approach provides a general framework that can be applied to evaluate SEAs elsewhere in the world from a biodiversity and ES conservation perspective.