In September of 1950 there were more than 10000 inhabitants in Sillamäe.
On the 16th May 1950 the ministerial council published the decree on which the working settlement of Sillamäe became a town with the same name. The town was formed, but according to the decree, it was subordinated to the city of Narva. But circumstances changed: Sillamäe increased to the size of town because of the fast development of its industry. Sillamäe had a special condition: its secret industry, the fact that it was located on sea shore and nobody could enter the town without special permission. At that time many town institutions were subordinated to state institutions: security, ministry of internal affair and prosecutor institutions. Therefore there was a question on making Sillamäe a town, submitting directly to the state. Thus the town grew rapidly (In spite of being almost destroyed during World War II, town as built and in 1950 there were 10000 inhabitants). Besides, its industry was unique.
Sillamäe got the status of town in 1957.