An inductive ignition system for low powered internal combustion engines comprises a voltage generator (10) having a magnetic circuit (16) linked with an ignition coil (17,18) connected to a spark plug (CD). The voltage generator (10) periodically produces alternating voltage signals (VL) each comprising a first and a second half wave (S1,S2) of a first polarity, and an intermediate half wave (S3) of opposite polarity. The voltage signals are used in a differentiated way to supply a microprocessor (Q1) of an ignition control circuit (21), with event signals correlated to the polarities of the voltage half waves (S1,S2,S3), and to the rotational speed and direction of rotation of the engine. The microprocessor (Q1) is programmed to control the flowing of the current (IL1) through the primary winding (17) of the ignition coil (17,18) during the second voltage half wave (S2) of each voltage signal (UL), at the starting, and during the intermediate half wave (S3) during the running of the engine, to generate ignition sparks at differentiated advance angles.