In recent years, some research has focused on the importance of the origin of an oil shock for macroeconomic dynamics in both oil-exporting and importing countries. The existing literature lacks a proper open Stochastic Dynamic General Equilibrium (DSGE) framework to investigate the effect of the origins of oil shocks on macro variables in a two-country model consisting of an oil-exporting county and an oil-importing country. To this end, we develop and solve a new Keynesian DSGE model to show how the different oil shocks originating from oil supply or oil demand, might have diverse impacts on key macroeconomic variables in oil-exporting and importing counties. For the case study, we use data from Iran as an example of an oil-exporting country that trades with the rest of the world. Our DSGE model is estimated by using the Bayesian method for the period 1986:1-2017:4. The result shows that an oil shock originated from the shortage of oil supply (an exogenous decrease in Iranchr('39')s oil production) decreases total production, non-oil trade, employment, inflation and consumption in this oil-exporting country. While a negative oil supply shock increases production costs and reduces production and consumption in Iran. However, an oil shock originated from an increase in the demand for oil raises output, non-oil trade, employment, consumption, and inflation in Iran as an oil-exporting country while a demand-side oil shock boosts production and increases inflation in this country.