A mini-sized heat-dissipating module includes a miniature heat-dissipating plate and a miniature fan unit. The miniature heat-dissipating plate has an assembling space, at least one airflow channel and at least two engaging members. The assembling space, the airflow channel and the engaging members are provided on a top surface of the miniature heat-dissipating plate, wherein the assembling space is arranged between the two engaging members. The miniature fan unit has an air inlet, an air outlet and a fan wheel. The miniature fan unit is securely engaged between the two engaging members of the miniature heat-dissipating plate when assembled. The fan wheel of the miniature fan unit takes up a maximum area less than 1.6 cm.sup.2 for rotation.