<b><i>Aim:</i></b> This study was performed to evaluate maternal changes in laboratory characteristics after fetoscopic laser photocoagulation (FLP) for twin-to-twin transfusion syndrome (TTTS). <b><i>Methods:</i></b> A retrospective review was conducted among 30 women with monochorionic diamniotic twin pregnancy with TTTS who underwent FLP at 16–26 weeks of gestation. Maternal laboratory parameters were measured before and after FLP. <b><i>Results:</i></b> The pre-FLP mean hemoglobin level (10.0 g/dL), hematocrit level (30.0%), platelet count (229 × 10⁹/mL), fibrinogen level (461 mg/dL), and antithrombin activity (96.8%) decreased after FLP (8.5 g/dL, 25.5%, 204 × 10⁹/mL, 403 mg/dL, and 83.6%, respectively) and returned to normal spontaneously within 2 weeks (9.6 g/dL, 29.4%, 293 × 10⁹/mL, 460 mg/dL, and 102.4%, respectively). The D-dimer level before FLP (2.41 μg/mL) increased after FLP (4.28 μg/mL), and the elevated level was maintained for 2 weeks (3.24 μg/mL). The symptomatic venous thromboembolism (VTE) was not detected after FLP in any of the 30 patients. However, one woman had pulmonary embolism after subsequent cesarean section. <b><i>Conclusion:</i></b> Changes in maternal anemia and coagulation/fibrinolysis after FLP for TTTS returned to normal spontaneously within 2 weeks. Maternal elevation of D-dimer level after FLP might be a warning indicator of VTE.