Wide‐line nuclear magnetic resonance (NMR) was used to determine the oil content from primary groats of more than 4,000 entries of the world oat (Avena sp.) collection. Weight per groat, based on the mean weight of the same primary groats used for oil determinations, was also determined.Oil content varied from 3.1 to 11.6%, with a mean oil content of 7.0%. Ninety percent of the entries ranged from 5 to 9%, but five entries contained more than 11%, while 25 contained less than 4% oil. Groat weight of entries ranged from less than 10 mg to 41.2 mg, with a mean weight for all entries of 26.2 mg. Most of the observations (85%) ranged from 20 to 32 mg per groat.A positive correlation coefficient of .ll between oil content and groat weight was obtained. While this was statistically significant, based on more than 4,000 d.f., it was considered too small to have practical importance in oat breeding.