Poland’s syndrome is a rare congenital disorder consisting of unilateral agenesis or hypotrophy of pectoralis major muscle associated with thoracic and/or variable ipsilateral upper limb anomalies. The estimated incidence is 1 to 3 in 100.000 newborns, tending to affect more male patients, with a ratio of 3:1, and in 75% of the cases the anomalies are present on the right side. The disease is defined as a “non-specific developmental field defect”. The current hypothesis is that it occurs around the 6th week of fetal development and is caused by a diminished or disrupted blood flow of the subclavian artery proximal to the origin of the thoracic artery but distal to the origin of vertebral artery. We present the case of a term (39 weeks) newborn Romanian female, after a caesarian section performed in “St. Pantelimon” Emergency Hospital from Bucharest, with unilateral breast and chest wall asymmetry along with upper limb abnormalities, located on the left side. The newborn had normal respiratory and cardiovascular parameters, but clinical examination revealed left-right asymmetry, with congenital absence of the left pectoralis major muscle and agenesis of the left breast with associated athelia. Another abnormality was found in the left upper limb as the patient was born with partial cutaneous syndactyly involving the third and the fourth fingers of the left hand. Chest radiograph showed the absence of the anterior costal arches from T3 to T10 vertebrae. Although recent genetic studies sustain the theory that there are several genes involved in different inheritance patterns, in our case the Poland syndrome occurred as a sporadic event as there was no evidence of congenital malformations in the patient’s family. A particularity of this case is that the newborn is a female and all the developmental anomalies were located on the left side of the body, which represent 25% of the overall cases. Therefore, the rarity of this case increases significantly. The risk factors remain unknown for this case, as there was no additional risk of Poland syndrome caused by smoking. We have to take into consideration that the patient is a newborn and that clinical manifestations may appear later in time, along with hematologic complications, so a close follow-up of the case is necessary. The proper time for surgical reconstruction has to be carefully and multidisciplinary selected in order to achieve the best result.