An experiment was conducted in an Oxisol (Tropeptic Haplorthox) in northwestern Puerto Rico to evaluate the potential for Irish potato production in this kind of soil at low elevations. Eleven varieties were tested in a partially balanced incomplete block design with 4 replications. The crop was planted in December 1974 and harvested after 109 days. Marketable yields ranged from 14.0 to 22.4 t/ha. Varieties Hudson, Red Lasoda, Red Pontiac and Chieftain yielded over 20 t/ha of marketable Irish potatoes. Sebago was the lowest yielder. Percentage of marketable yields ranged from 90 to 97. Total yields followed the same trend as marketable yields. Hudson outyielded all varieties except Red Lasoda in terms of U.S. No. 1 tubers. There was an apparent negative relationship between disease rating and total yield. It is inferred that Irish potato production can be a profitable enterprise under local conditions if good management practices are followed.