An innovative wireless device for bioimpedance analysis was developed for post-dual-site free vascularized lymph node transfer (VLNT) evaluation. Seven patients received dual-site free VLNT for unilateral upper or lower limb lymphedema. A total of 10 healthy college students were enrolled in the healthy control group. The device was applied to the affected and unaffected limbs to assess segmental alterations in bioimpedance. The affected proximal limb showed a significant increase in bioimpedance at postoperative sixth month (3.3 2.8, 3.6, = 0.001) with 10 kHz currents for better penetration, although the difference was not significant (3.3 3.3, 3.8) at 1 kHz. The bioimpedance of the affected distal limb significantly increased after dual-site free VLNT surgery, whether passing with the 1 kHz (1.6 0.7, 3.4, = 0.030, postoperative first month; 2.8 1.0, 4.2, = 0.027, postoperative third month; and 1.3 1.3, 3.4, = 0.009, postoperative sixth month) or 10 kHz current ((1.4 0.5, 2.7, = 0.049, postoperative first month; 3.2 0.9, 6.3, = 0.003, postoperative third month; and 3.6 2.5, 4.1, < 0.001, postoperative sixth month). Bioimpedance alterations on the affected distal limb were significantly correlated with follow-up time ( = 0.456, = 0.029 detected at 10 kHz). This bioimpedance wireless device could quantitatively monitor the interstitial fluid alterations, which is suitable for postoperative real-time surveillance.