We studied the effects of the Lymphapress pump (LP; Global Medical Imports, Digby, NS, Canada) retrospectively on 16 children with primary or secondary lymphedema of the upper or lower extremities by measuring the volume and circumference of the limbs before and after treatment. We reviewed medical charts for data on age, sex, length of disease process, grade of lymphedema, frequency and duration of treatment, and pump pressures used. We recorded changes in limb size before and after pumping in terms of the mean percentage difference between the affected and unaffected limb at both time points to allow for growth of the child and the extremity. On volumetric measures, thirteen (93%) of the subjects showed a clinical trend towards sustained maintenance or reduction in size of the lymphedematous limb(s). The reduction in the pump pressure at start of the treatment to that required to maintain the size of the limb was statistically significant (p = 0.0036). Fourteen (88%) of the subjects had no complications directly attributable to the pump, whereas two had complications that were probably unrelated to LP. Overall, there was a clinical trend towards reduction or maintenance of the lymphedematous limb size in children using LP without notable adverse sequelae.