A shuttleless loom weft detaining device including a drum rotatable in synchronism with the operational cycle of the loom, the drum being formed with a frustoconical section and a cylindrical section, a first weft yarn catching member disposed between the frustoconical and cylindrical sections to catch a first portion of a weft yarn to detain the weft yarn on the drum for the period of weft picking, and a second weft yarn catching member associated with the cylindrical section of the drum to catch a second portion of the weft yarn to detain the weft yarn on the drum for the period other than the weft picking period, thereby effectively preventing shortpicks of the weft yarn into the shed of warp yarns.