Machine for the production of bottles by means of stretch blow-molding of preforms, comprising a sequence of processing stations starting with a station for receiving at least one preform for insertion thereof in a mold and ending with a station for releasing the corresponding bottle produced, gripping means being movable between the stations so as to grip the at least one preform in the receiving station and transport it between the processing stations for converting it into the bottle by means of stretch blow-molding and as far as the release station, whereby it comprises, after the processing stations and before the machine outlet, a checking station in which the following are present: - gripping means for retaining the bottle by its neck; - a test probe with means suitable for sealing the mouth of the bottle; - pressure means for introducing into the bottle a pressurized fluid via the test probe; - measurement means for measuring at least one significant parameter of the pressurized fluid supplied to the bottle; - a control circuit designed to: - receive the measurement of the at least one parameter from the measurement means; - compare this measurement with a predetermined reference value; and - signal any anomaly resulting from the comparison and indicating a loss of leak-tightness of the bottle; the gripping means of the checking station being the gripping means which grip the neck during processing of the bottle between the stations and which move between the stations by means of a carousel from the receiving station to the release station, characterized in that: in the release station there is a discharging and reject system which is operated by the control circuit so as to convey away the bottles either to an output line or to a reject zone. - gripping means for retaining the bottle by its neck; - a test probe with means suitable for sealing the mouth of the bottle; - pressure means for introducing into the bottle a pressurized fluid via the test probe; - measurement means for measuring at least one significant parameter of the pressurized fluid supplied to the bottle; - a control circuit designed to: - receive the measurement of the at least one parameter from the measurement means; - compare this measurement with a predetermined reference value; and - signal any anomaly resulting from the comparison and indicating a loss of leak-tightness of the bottle; the gripping means of the checking station being the gripping means which grip the neck during processing of the bottle between the stations and which move between the stations by means of a carousel from the receiving station to the release station, characterized in that: in the release station there is a discharging and reject system which is operated by the control circuit so as to convey away the bottles either to an output line or to a reject zone. - receive the measurement of the at least one parameter from the measurement means; - compare this measurement with a predetermined reference value; and - signal any anomaly resulting from the comparison and indicating a loss of leak-tightness of the bottle; the gripping means of the checking station being the gripping means which grip the neck during processing of the bottle between the stations and which move between the stations by means of a carousel from the receiving station to the release station, characterized in that: in the release station there is a discharging and reject system which is operated by the control circuit so as to convey away the bottles either to an output line or to a reject zone. in the release station there is a discharging and reject system which is operated by the control circuit so as to convey away the bottles either to an output line or to a reject zone.