The Indianapolis-based trucking-fleet insurer earned $14.1 million, or 96 cents per share, compared with $6.3 million, or 41 cents per share, in the prior-year period.
The earnings far exceeded analyst expectations of 39 cents per share.
Investment gains added 55 cents per share to second-quarter profit, compared with a loss of 13 cents per share the same time a year ago.
Quarterly revenue rose from $49.3 million to $58.6 million.
Premiums written by Baldwin's insurance companies were flat compared with the second quarter of 2008.
Company shares increased nearly 2 percent, to $21.49 cents each, in mid-morning trading.