There is no way to change font in a UISearchBar, but it’s possible with a little trick:
for(int i =0; i<[searchbar.subviews count]; i++) {
if([[searchbar.subviews objectAtIndex:i]
isKindOfClass:[UITextField class]])
[(UITextField*)[searchbar.subviews objectAtIndex:i]
setFont:[UIFont
fontWithName:@"Helvetica" size:12]];
}