Preheat grill to medium heat.
Brush pineapples with olive oil. Place spears on hot grill and grill until pineapple is browned and juicy, turning occasionally until all sides are grilled. Remove from grill and set aside to cool.
When pineapple is cool, cut into small pieces.
In large bowl combine avocado, red onion, cilantro, jalapeno and lime juice. Mash together with a fork until desired consistency is reached.
Gently stir in the grilled pineapple.
Season with salt and pepper to taste and serve immediately with tortilla chips.