If using wooden skewers, soak them in water for at least 30 minutes before assembling.
Thread chicken cubes, green peppers, red peppers, red onion, and pineapple chunks alternately onto skewers.
In a medium bowl, whisk together barbecue sauce, pineapple juice, and soy sauce until smooth.
Place the assembled kabobs in a shallow dish.
Brush about one-third of the marinade over the kabobs, reserving the remaining sauce for grilling.
Cover and refrigerate for 15 to 20 minutes.
Preheat the grill to medium heat and lightly oil the grates.
Place the Pineapple BBQ Chicken Kabobs on the grill.
Grill for 12 to 15 minutes, turning frequently.
Brush with the remaining barbecue sauce mixture during cooking.
Continue grilling until the chicken reaches an internal temperature of 165°F (74°C) and the vegetables are tender.
Remove from the grill and serve immediately.