Callable bonds give the option to the issuer to cancel the bond before the maturity date. Of course, by saying cancelling the bond, we mean redeeming the bond and pay the agreed price to the bond holder. The fact that this bond has an option attached make it more expensive for the issuer so it will usually have a higher premium (or coupon rate). To answer your question, a callable bond does not have any characteristic that will make it less safe. It can be more or less profitable (depending on the market conditions) but the option is always at a higher rate than the issue price so the bond holder does not lose money. As with all investment, the risk of the default of the bond issuer should be assessed.