Bring a large pot of salted water to a boil. Add potatoes and cook until tender but still firm, about 12 - 15 minutes. Drain, cool, and chop and place in large bowl.
In a medium bowl, combine the mayonnaise, mustard, sour cream, chopped pickle, onion, celery, pimentos, green olives, parsley, pepper and salt. Blend until mixed well. Pour the mayonnaise mixture into the large bowl with the potatoes. Carefully mix until evenly covered. Chill and serve when cold.