A process for manufacturing ladders comprises the following steps: arranging a plurality of rungs (2) of a material comprising a plurality of reinforcing fibers (2a) associated with a binding resin (2b) and each having at least one coupling portion (2c); arranging at least one primary upright length (3), preferably of a material comprising a plurality of reinforcing fibers (3a) associated with a binding resin (3b); mechanically linking the coupling portions (2c) of the rungs (2) to corresponding engagement regions (3c) of the primary upright length (3). The linking step involves bringing at least one of the binding resins (2b, 3b) to the fluid phase at least close to the engagement regions (3c) and/or the coupling portions (2c). The binding resins (2b, 3b) are thermoplastic polymeric materials and the step of bringing the binding resins (2b, 3b) to the fluid phase takes place by melting of the binding resins (2b, 3b). The binding resins (2b, 3b) are chemically similar to each other and they are preferably identical with each other.