A female infant of a diabetic mother born through LSCS at 39 weeks of gestation with a birth weight of 2908 grams was noted to have a paucity of movement of the left upper limb soon after birth. The extremity was pale, had markedly deranged perfusion, and was cold to touch with absent brachial, radial, and ulnar arterial pulsations. There was a swelling noted over the middle of the left arm, which was tender and associated with crepitus suspicious of a fracture. The right upper limb and lower limbs were normal. An urgent X-ray of the left upper limb showed a displaced fracture of the left humerus fracture and the Doppler study revealed absent flow in the brachial artery distal to the fracture site without thrombus. Urgent close reduction of the fracture following which the doppler showed a thrombus in the brachial artery extending up to its bifurcation. The thrombosis was managed medically with low molecular weight heparin and aspirin. There was a gradual improvement of limb perfusion with normalcy achieved on day 3 of life with no residual complications even on follow-up. The workup of neonatal thrombosis, its immediate management and current evidence for the same have been discussed in detail.