Over high heat, bring a large pot of salted water to a boil. Add green beans and cook until crisp tender, approximately 3-4 minutes. Drain the green beans and then transfer to a large bowl of ice water to prevent further cooking.
Remove green beans from the ice bath and pat dry before adding to a large glass or other non-reactive bowl. Add the tomatoes, basil, parsley, olive oil, and vinegar to the bowl and toss to combine. Season with salt and pepper, to taste.
Gently fold in crumbled Feta cheese and serve immediately. Salad can also be chilled and served cold.