Although gait problems have been reported in patients with lower limb lymphedema (LLL), the gait pattern (GP) changes have not been documented yet. However, it is possible that patients with LLL show abnormal GP that can be related to biomechanical complications related to osteoarthritis or falls affecting the quality of life. Ground reaction force analysis during gait allows objective assessment of the patients and it can be used to plan a rehabilitation approach. Objective: To analyze the GRF during gait in patients LLL. Methods: An experimental descriptive study was realized with twenty-three LLL patients, both unilateral and bilateral and classified as moderate and severe, participated in the experiments. The patients walked on a force plate while the three ground reaction force (GRF) components, vertical, mediolateral (M-L) and anteroposterior (A-P), under their feet were recorded and analyzed. Results: In the patients with unilateral lymphedema, either moderate or severe, the vertical GRF components of the affected limb were similar to the sound one and also resembling those found in healthy adults. The M-L GRF was smaller in the non-affected side. In patients with bilateral lymphedema gait speed was significantly slower. More interestingly, the vertical GRF pattern was flat, not showing the typical 2-peak shape. Finally, the large M-L forces found suggest gait stability problems. Conclusions: The patients showed abnormal GRF patterns, including compensation with the non-affected leg. The GRF variability was higher in the patients with severe unilateral lymphedema. Bilateral lymphedema results in lower A-P forces. Stance phase duration was longer in patients with bilateral and severe lymphedema.