The metalation of Br–ThPy–Br (Th: thiophene-2,5-diyl; Py: pyridine-2,5-diyl) and 2-iodo-5-bromopyrimidine with i-PrMgCl proceeds regioselectively. The cross-coupling polycondensation of regioselectively metalated intermediates gives head-to-tail π-conjugated poly(thiophene–pyridine) and polypyrimidine, respectively, and their packing structures in the solid state and optical data are discussed.