note ; National audience ; The current study examines the relationship between the world oil price and aggregate demand in a developing country, Tunisia, via the interest rate channel by means of univariate and multivariate cointegration analysis with multiple structural changes. Results of the study indicate that oil price, by impacting the price level positively, negatively impacts real output. The results also indicate that monetary policy is initially eased in response to a surge in the price of oil in order to lessen any growth consequences, but at the cost of higher inflation. The ensuing higher inflation, however, prompts a subsequent tightening of monetary policy leading to a further decline in output. In addition, output does not revert quickly to its initial level after an oil price shock, but declines over an extended period.