Indoleamines such as melatonin and serotonin have been found not only in mammalians but also in diverse living organisms, microorganisms, and plants. In the last decade of investigations, these molecules have been found in various edible plants and processed foods. Melatonin has been reported in edible fruits (grape, banana, strawberries, apple, pineapple, Kiwi fruit, tart cherries, etc.), vegetables (tomato, pepper, mushroom, cabbage, cauliflower, cucumber, carrot, beetroot, etc.), nuts and raw seeds (walnuts, sunflower, green cardamom, fenugreek, white and black mustard, etc.), juices and beverages (wines, green and roasted coffee beans, decoction brew). Also, the intake of these indoleamines-containing foods could significantly increase the melatonin/serotonin concentration in human serum, indicating these indoleamines could provide beneficial health effects. Studies have shown that melatonin has many bioactivities, such as antioxidant, anti-inflammatory, enhancing immunity, anticancer, improving circadian cycle, cardiovascular protecting, antidiabetic, anti-obese, antiaging, and neuroprotection. The nutritional implications of indoleamines as bioactive molecules are well documented and hence, it becomes one of the thrust areas of interest to explore their levels in various edible plants and food products. This chapter describes the occurrence of melatonin and serotonin in selected edible plants, fruit, vegetables, and processed foods and their bioavailability along with possible human health effects.