Hypothyroidism is a manifestation of multi-hormonal resistance in pseudohypoparathyroidism type Ia (PHP Ia). The aim of this article was to present 9 months old male patient as case of congenital hypothyroidism. We describe a 9 months old male diagnosed with congenital hypothyroidism at age 1.5 month, who developed later (at age 5 months) cyanotic attack associated with hypocalcaemia, hyperphosphatemia, and hyperparathyroidism, patient had typical characters of AHO, so the diagnosis of Pseudohypoparathyroidism 1a associated with resistance (TSH) was established. Children diagnosed with PHP 1a should be further evaluated for associated resistance endocrinopathies. The literature on pseudohypoparathyroidism is reviewed with special emphasis on the misdiagnosis with congenital hypothyroidism.