The purpose of the present study is survey of extraction conditions and exploring antioxidant potential of the non-traditional for the Bulgarian ethno-medicine wild herb Cistus incanus widespread in Strandja Mountain. The influence of the extraction time (0–500 min) and solvent composition (0–50% ethanol in water) on the polyphenols, flavanoids yields and on antioxidant capacity of the extracts of leaves, stalks (wood parts) and buds mixture were studied. The antioxidant capacity (AOC) was evaluated by use of scavenging assays of 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals. Total phenolic and flavonoid contents were quantified using UV–vis spectrometry. Optimal yield of desired components has been obtained with 30% ethanol in water solvent at 390th min extraction time. In addition, the evaluation of the influence of the seasonality (winter and summer Cistus incanus), and of the different areal parts—hard-coated seeds; buds, and mixture of leaves and stalks of the wild plant through the presence of polyphenols, flavanoids and AOC were investigated. Present work revealed the high values of the polyphenols, flavanoids, the high AOC not only in the summer leaves, but also found in the winter leaves, hard-coated seeds, buds and stalks. Based on the obtained results the Cistus incanus from Strandja mountain could be a new excellent source of natural antioxidants in food and pharmaceutical industries.