Samsung has admitted some of its Chinese suppliers had "inadequate" employment practices but insisted that none used child labour.
The world's biggest manufacturer of smartphones said it had inspected 105 Chinese partners following a report by China Labor Watch (CLW), which claimed at least one supplier was using children aged under 16.
The South Korean company vowed that it was "a top priority" to stamp out practices such as excessive overtime and fines for lateness, which US-based watchdog CLW found in its audit.
While the company behind Galaxy smartphones and tablets said it found no children being used in factories, it said contracts with suppliers which used child labour "will be terminated". It came as Apple widened its US lawsuit against Samsung, alleging that it infringed more patents, including one on the latest Galaxy S3 models.