Aamir had first highlighted the issue on his TV show "Satyamev Jayate".
An official in the chief minister's office Friday said Aamir had written a letter to Nitish Kumar in this connection.
"I urge you to work towards bringing about this dynamic revolution of making generic medicines easily available across the state of Bihar," Aamir said in his letter to Nitish Kumar.
An official in the health department said Aamir requested Nitish Kumar after Health Minister Ashwani Kumar Choubey sought the actor's help in creating awareness and popularise generic medicines among the people.
Aamir said in his letter that generic medicines would make a huge difference to the middle class, lower middle class and the poor.
Aamir wrote to Nitish Kumar that Rs.35,000 crore of generic medicine manufactured in India were exported annually to other countries.
Choubey said the Bihar government had already decided to provide generic medicines in all government hospitals and health centres, but the policy was yet to be implemented.
Aamir had also met Rajasthan Chief Minister Ashok Gehlot after hosting a show on the issue and urged him to take steps to curb incidents of female foeticide in the state.