This paper studies how Slovakia’s adoption of the euro in 2009 affected the structural macroeconomic relationships governing inflation, output, and monetary policy. We estimate a two-country structural VAR for Slovakia and the rest of the euro area, where we allow Slovak structural relations to differ across regimes. We find that euro adoption was associated with a pronounced flattening of the Slovak Phillips curve and with a marked change in the role of interest rates in aggregate demand. After euro adoption, Slovak demand shocks became much less inflationary, supply shocks generated smaller output and inflation responses, and domestic impulse responses moved substantially closer to their euro-area counterparts. The convergence is strongest on the supply side and in the immediate absorption of shocks, while demand-side convergence is more selective. The inflation sensitivity of demand remains relatively stable, whereas the interest-rate semi-elasticity shifts sharply towards zero. We interpret these results as evidence that monetary integration can induce genuine structural convergence in small open economies by strengthening nominal anchoring, changing the information content of domestic interest rates, and reinforcing real economic integration beyond the mechanical loss of an independent monetary policy.