Hospital-grade electric pumps may be useful to initiate and sustain adequate milk production for mothers who are unable to breast-feed their babies hospitalized at special care nurseries (SCN), but their cost is generally not affordable for SCN and for most mothers in developing countries. Therefore, manual breast pumps (MBPs) can be an alternative, but the best option is unknown considering clinical parameters and mothers' preference from among currently available MBPs. To compare the effectiveness of four MBPs in terms of milk volume, nutritional composition, and breast emptying in order to assist in making a choice for health care personnel and mothers in SCN settings. Duration of expression and maternal preference were also evaluated as secondary outcomes. Mothers of preterm infants used 4 MBPs in a random order, 2 with a squeeze-handle mechanism (Isis and Harmony) and 2 with a cylindrical mechanism (Little Heart and Evenflo), both at the hospital and in home settings using each pump over one 24-hour period. Milk volume, nutritional composition, breast emptying, and duration of expression were not different among MBPs. Scale of maternal preference rated higher those with the squeeze-handle mechanism than the cylindrical mechanism (p < 0.05). There was no difference found in the effectiveness across the four pumps tested. The mothers' rating for comfort and ease of use showed a marked difference between pumps. These factors, plus cost, need to be considered when evaluating manual pumps for use in SCN settings in developing countries.