Most newly planted olive (Olea europaea L.) orchards are irrigated and harvested mechanically. We assessed the effects of olive storage temperature and duration on the resultant oil’s quality in three cultivars from modern orchards. Oil acidity increased with storage temperature and time, most markedly in ‘Barnea’ and least in ‘Koroneiki’. In ‘Koroneiki’, after 9 days in cool storage (4 and 10 °C), free fatty acid (FFA) level remained constant. Polyphenol (PP) content behaved differently among cultivars: in ‘Picual’, it was relatively invariable; in ‘Barnea’, it decreased moderately; and in ‘Koroneiki’, it decreased sharply to half of its initial value in 4 °C storage and one-sixth its initial value in room temperature storage after 23 days. Peroxide value (PV) did not increase during the storage period and did not appear to be affected by temperature. Thus, different cultivars show different responses to storage, and fruit originated from modern orchards are not necessarily more sensitive to storage than those from traditional orchards.