A system for detecting the walk of a person has a housing (BT) with at least a biaxial movement sensor (CM). The housing is attached to the upper portion of the body of the person, so that a first measurement axis of the sensor (CM) coincides with the anteroposterior axis (AP) or the vertical axis (VT) of the body and so a second measurement axis of said sensor (CM) coincides with the mediolateral axis (ML) of the body. An analysis means (MA) analyzes the measurements delivered by the sensor (CM). The analysis means includes a processing means (MT) for processing over a time window the measurement signals delivered by the sensor (CM), which includes means for searching for a dominant frequency (MRFD) in said signals. The analysis means also includes a detection means (MD) for detecting the walk of the person when a ratio between the dominant frequency of the signal of the first measurement axis and the dominant frequency of the second measurement axis, or between the dominant frequency of a Euclidian norm of the vector of measurements transmitted by the sensor (CM) and the dominant frequency of the signal of the second measurement axis, is substantially equal to two.
