Abstract: This invention relates to a fiber optic cable construction for optical well monitoring systems, socalled FOWM cables. Such cables have to withstand high temperature, high hydrostatic pressure and an aggressive environment. The fiber optic FOWM cable comprises a first layer of elements stranded around a central core (6;16;24). At least one of said elements is constituted by a tube (4,5;12,13;22,23) within which there is loosely inserted an optical fiber element (2,3;14,15;26,27). The tube (4,5;12,13;22,23) has a diameter which is less than that of the other stranded elements (7;11;21) of the first layer, so as to provide mechanical protection of the tubes and optical fibers.