Review of the literature indicates that imbibitions in water-wet matrix blocks is commonly considered to be counter-current. Despite this general belief, our experimental and theoretical studies indicate that co-current imbibitions may be the dominant mechanism. Using numerical simulation of the imbibitions process it is found that oil is predominantly recovered by co-current imbibitions, and the time for this recovery is only a fraction of that required for counter-current imbibitions. This is because in counter-current imbibitions, oil is forced to flow in the two-phase region. In co-current imbibitions, however, oil is free to flow in the single phase region. This study reveals that co-current imbibitions is much more efficient than counter-current imbibitions.