The EU is the first regional organization that has strived to upgrade its observer function in the UNGA and on 3rd May 2011, with the UNGA resolution A/RES/65/276 gained an enhanced observer status. Since the adoption of this resolution has created a framework that brings changes to the functioning of the EU in the UNGA, my master's thesis aims to analyze the impact of the resolution on the EU MS' voting coherence in the UNGA on nuclear-related resolutions. Since the disagreement between the EU MS in the UNGA is the highest regarding resolutions dealing with nuclear weapons, it seems appropriate to analyse to what extent the adoption of A/RES/65/276 contributed to the EU's ability to present a common position in the UNGA or the ability to »speak with one voice« when discussing such a controversial topic. I intend to identify this on the basis of a mixed method, i.e. a quantitative analysis of the EU MS' vote on the subject of resolutions dealing with nuclear weapons and qualitative analysis of possible changes of the EU's nuclear arms standpoints in the eight year period before and after the adoption of A/RES/65/276. Findings show that the UNGA Resolution no. A/RES/65/276, did not contribute to a greater coherence in the EU MS's voting in the UNGA when voting on nuclear weapons resolutions. EU MS remain divided on nuclear disarmament issues, with both nuclear and non-nuclear states maintaining strong national preferences.