A vacuum-cleaner nozzle assembly has a base nozzle forming a downwardly open suction mouth having a lower edge and of a predetermined horizontal width measured in a direction transverse to a working direction of the base nozzle. A first and second expansion fitting each form a respective downwardly open suction mouth of a predetermined horizontal width substantially greater than the width of the mouth of the base nozzle, the width of the second fitting being greater than that of the first fitting. Each expansion fitting has an upwardly open seat complementary to and fittable with the lower edge of the base nozzle and a suction port in the seat such that, when the base nozzlenestle is fitted to the seat, aspiration through the base nozzle draws air upward from the suction mouth of the respective expansion fitting.