Captain Nadeem and his wife were on way from their residence when some unknown armed men opened fire at them on Rahmatullah road near Karachi Stadium, TV channels reported.
Both were rushed to a near-by hospital where Nadeem succumbed to his injuries.
TV channels showed a bullet-ridden red Suzuki car.
The incident comes on the day when Prime Minister Nawaz Sharif is to hold a special cabinet meeting in the city to chalk out a strategy to end the cycle of violence that has plagued the business hub.