A patient-specific navigational guide for use in spinal surgery, comprising two tubular guiding members integral with a supporting frame and extending from a proximal opening to a distal opening for guiding a surgical operation on a patient's vertebra. The contact members are designed to mate with a corresponding plurality of contact areas on the patient's vertebra in order to define a unique coupling configuration of the patient-specific navigational guide on the patient's vertebra. Said contact members comprise at least one pair of a first main contact member, designed to abut, at least partially, on the upper articular process, or facet, of the patient's vertebra, and a pair of second main contact members, designed to abut on a contact area corresponding to the lamina of the patient's vertebra. Said tubular guiding members each have a slot extending from the proximal opening to the distal opening.