The log wood of three cultivars of poplar introduced in the Province of Valdivia, Chile, and grown without management, was characterized. Volume and quality yield in saw timber from a portable sawmill were determined, as were the required artificial drying processes. The best results in quality and timber production were achieved with Populus x euramerica cv. I-488. Cultivars I-72 and cv. I-161 presented significantly lower volumes and mainly qualities 2 and 3. The percentage of utilization for all cultivars was 61%; 36% was accounted for by edge loss and 3% by sawdust. After drying, Populus x euramericana cv. I-488 presented the best results in relation to final moisture, drying time, and defects. The most frequent defects were spring and bow. The presence of knot, false heartwood, reaction wood, and growth tensions were the most negative defects found in these cultivars.