This flag was adopted by the Moldavian SSR on January 31, 1952.
Prior to this, the flag was red with the gold hammer and sickle in the top-left corner, with the Cyrillic characters РССМ (RSSM) above them in gold in a serif font.
Between 1924 and the adoption of the flag in the 1940s, part of Moldova was organized as the Moldavian ASSR with the Ukrainian SSR, and used a red flag, with the gold hammer and sickle in the top-left corner, above the Cyrillic characters УРСР (URSR, Ukrainian initials of Ukrainian SSR) and the Latin characters RSSU. Between 1929 and 1937, the hammer and sickle was removed, and from 1935 on the Latin characters were removed.
The flag closely resembles the current Flag of Transnistria.