Capsicum is one of the most economically important genera in the Solanaceae family. Capsicum fruits (peppers) are rich in phytochemicals with high nutritional value and significant health-promoting characteristics. The phytochemical profile of peppers consists of capsaicinoids, carotenoids, and phenolics, primarily. Currently, most of the pepper production is carried out under protected horticulture conditions. The objective of this article was to provide a comprehensive review on how light characteristics and manipulation by different horticultural technologies can affect the biosynthesis and accumulation of phytochemicals in Capsicum fruits. The use of shade nets or plastic covers to reduce light intensity does not seem to yield consistent responses on the phytochemical profile, as the final profile results from the interaction of several factors. Other factors involved in the accumulation of phytochemicals include temperature, water availability and plant nutrition. Exposure of plants to supplemental light with specific wavelengths (using LEDs) seems to result in a more precise stimulation of specific metabolites. In this article, we examine the effects of light irradiance and spectrum on the specific phytochemicals of Capsicum fruits.