At 4,140mm long, 1,780mm wide and 1,660mm tall, it's 594mm longer, 153mm wider and 175mm taller than the three-door 500. The Italian company says its boot has a capacity of close to 400 liters and that is is able to hold up to five roller suitcases or a full-size pushchair.
In Geneva, Fiat presented the five-seat version of the 500L, but the company is also planning to introduce a longer variant with seven seats.
Series production of the 500L will begin at Fiat's Serbian plant Kragujevac later this year with European sales to start in the fourth quarter of 2012.
It will be offered with two petrol engines, a 0.9-liter turbocharged twin-cylinder unit and a 1.4-liter unit, plus a 1.3-liter Multijet II turbo diesel.
According to sources, Fiat will offer the five-seat version of the 500L in North America, but not the seven-seat model.