This study aims to explore the relevance (costs and benefits) of coffee growing in Idjwi based on the activities already implemented by coffee stakeholders in this region. Overall, this research was based on a coffee yield study in the territory of Idjwi. The combination of three methods and three data collection techniques led us in this study to use the verification of our hypotheses. It appears from the analyses made that on average the operating costs are 213,379 FC with maximum loads of 1,880,000 FC and minimum of 315,00 FC, the quantity per season in kg and the average price are respectively 625.66 kg and 588, 62Fc, with relative maximums and minimums of 5099kgs, 45kgs and 600FC, 450FC. The found DW (Durbin Watson) statistic of 1.676 is less than 2, showing that the errors are not correlated or related. The Fisher test being equal to 0.000, lower than the threshold of 0.05 or 5%. We say the model is overall good. By interpreting the significant variables with respect to the threshold of 0.05, we have: - When the loads increase or vary by 1%, the production or the quantity produced per season also increases by 0.001. - When the price increases by 1%, the production or quantity produced per season also increases by 5.354. - When the profitability or yield increases by 1%, the production or the quantity produced per season also increases by 470,551. This leads us to say that if policies are needed to increase the quantity produced in the coffee sector in Idjwi, they must be primarily oriented on the three factors that were significant, in particular the price, the operating costs and the profitability in the business.