National Interstate Corporation Announces Quarterly Dividend

RICHFIELD, Ohio, Aug. 11, 2011 (GLOBE NEWSWIRE) -- National Interstate
Corporation (Nasdaq:NATL) announced that its Board of Directors approved a $0.09
per share dividend payable on September 12, 2011 to shareholders of record of
the Company's common stock as of the close of business on August 29, 2011.

The Company has paid a dividend each quarter since the 2005 fourth quarter and
increased it annually during the first quarter each year beginning in 2006.

About National Interstate Corporation

National Interstate Corporation (Nasdaq:NATL), founded in 1989, is the holding
company for a specialty property-casualty insurance group which differentiates
itself by offering products and services designed to meet the unique needs of
niche markets. Products include insurance for passenger, truck and moving and
storage transportation companies, alternative risk transfer, or captive programs
for commercial risks, specialty personal lines products focused primarily on
recreational vehicle owners and small commercial vehicle accounts, and
transportation and general commercial insurance in Hawaii and Alaska. The
Company's insurance subsidiaries, including the two primary insurers, National
Interstate Insurance Company and Vanliner Insurance Company, are rated "A"
(Excellent) by A.M. Best Company. Headquartered in Richfield, Ohio, National
Interstate is an independently operated subsidiary of Great American Insurance
Company, a property-casualty subsidiary of American Financial Group, Inc.
(NYSE:AFG) (Nasdaq:AFG).

CONTACT: Tanya Inama
National Interstate Corporation
877-837-0339
investorrelations@nationalinterstate.com