The value of the gold biscuits weighing more than 2.5 kilogram would be more than 78 lakh, a customs official said.
The woman had come to Kolkata from Bangkok on Monday night.
Officials of the intelligence wing of customs department found her behaviour to be suspicious and intercepted her, the official said.
During a search, the intelligence wing officials recovered nine gold biscuits from her bag and her clothes, and then she was arrested, he said.