Polythiophene and its derivatives are valuable conjugated polymers due to their physical properties and applications in various fields. Precursors of polythiophenes were conventionally obtained from petrochemical byproducts, which are non-renewable. Thiophene and its derivatives had been found naturally in Tagetes species such as Tagetes erecta, Tagetes tenuifolia, etc. Tagetes species produce 2, 2':5', 2''-terthienyl (Alpha-T), 5-(3-buten-1-ynyl)-2, 20-bithienyl (BBT), 5-(4-hydroxy-1-butynyl)-2, 20-bithienyl (BBTOH), and 5-(4-acetoxy-1-butynyl)-2, 20-bithienyl (BBTOAc), which are accumulated in different parts, specifically in the roots of the plants. These thiophene derivatives were extracted and identified by GC-MS, Uv-vis, FTIR and TLC analysis. The partially purified plant extract is polymerized through one step oxidative free radical polymerization to obtain polythiophenes. Product characterization has revealed that the selective polymerization of thiophene derivatives results in the phase-separated end product from the rest of the materials in the plant-extract.