The oil palm industry in Indonesia faces several challenges in its bid to adopt more sustainable practices. These challenges include finding ways to increase smallholder palm oil production and to promote benefit sharing with local communities. However, factors that influence oil palm yield and income among oil palm smallholdings are poorly known. We surveyed 379 households in 15 villages in Sumatra, Indonesia, to identify factors controlling smallholder yield and income. We found that decreasing monthly harvesting rotation of oil palm smallholdings decreases oil palm yield, whereby once-a-month harvesting resulted in the lowest annual fresh fruit bunch yields (14.82 t/ha). We also found that independent smallholder households receive lower gross monthly incomes compared to scheme and managed smallholder households, whereby independent smallholders received the lowest gross monthly income from oil palm cultivation (2.17 million Indonesian rupiah). Our results provide quantitative evidence that harvesting rotation and type of smallholder management are important constraints on oil palm yields and incomes of smallholders.