The 1999 Kmart 400 presented by Castrol Super Clean was the 14th stock car race of the 1999 NASCAR Winston Cup Series season and the 31st iteration of the event.

[3] Rusty Wallace, driving for Penske-Kranefuss Racing, would set the fastest time in the session, with a lap of 38.598 and an average speed of 186.538 mph (300.204 km/h).

[3] Jeff Burton, driving for Roush Racing, would set the fastest time in the session, with a lap of 38.489 and an average speed of 187.066 mph (301.054 km/h).

[5] The final practice session, sometimes referred to as Happy Hour, was held on Saturday, June 12, after the preliminary 1999 Michigan ARCA 200.

[3] Bobby Labonte, driving for Joe Gibbs Racing, would set the fastest time in the session, with a lap of 39.766 and an average speed of 181.059 mph (291.386 km/h).

[7] Jeff Gordon, driving for Hendrick Motorsports, would win the pole, setting a time of 38.514 and an average speed of 186.945 miles per hour (300.859 km/h).