The product packaging when I purchased at a retail chain advertised that it "Works with iPhone." Fundamentally it "works" with iPhone but only because it uses the same jack size as any generation iPod. However, technically, it does not "work as advertised" with an iPhone or in the presence of any cellular device period. Any cellular device coming within a foot of this thing's cable causes extreme interference. In the case of the iPhone the only way to prevent such interference is to turn on "Airplane Mode" within the phone's settings.Additionally the product fails to overpower other automotive transmitters and often gets drowned out by passing vehicles' transmitters.Overall I suggest you find a more powerful transmitter with better shielding from high-frequency signals.