Chile implemented a generic substitution policy in 2014 to improve access to medicines. This study aims to measure if the generic substitution policy had an effect on the sales volume and prices of referent and the branded generic products with demonstrated bioequivalence (BEQ) in the private pharmaceutical market. The volume and total private sales of medicines sold at private sector retail outlets between November 2011 and October 2016 were considered in the analysis. We calculated the total number of daily defined doses (DDD) by adding up the number of DDDs of different presentations with the active pharmaceutical ingredient (API). We determined the ratio of the median prices of all BEQ per DDD presentations compared with the median price of the corresponding referent presentations per DDD in 2011 and 2016. Sixteen APIs representing 231 different conventional-release presentations were included in the analysis. Overall, the volume of sales of the referent products decreased over time after the intervention. However, this reduction was not mirrored by an increase in the corresponding branded generic BEQ volumes overall. In all cases, the median price per DDD of the referent was higher than its BEQ counterpart in 2011 and 2016. Since referent products are more costly than branded BEQ generic products, reducing their consumption-and increasing the BEQ availability-should improve access to medicines in Chile. However, this must be accompanied by promotion of BEQ products to ensure savings for consumers in the long term. Future research should focus on identifying facilitating and inhibiting factors of generic substitution.