Abstract In the present work, combining polymerization‐induced self‐assembly (PISA) with self‐assembling peptides (SAPs) peptide−polymer hybrid nanostructures are prepared, harnessing the advantages of PISA and the self‐assembling driving force of SAPs. A tripeptide methacrylamide denoted as MAm‐GFF, where MAm, G, and F stand for methacrylamide, glycine, and phenylalanine, is copolymerized with glycerol monomethacrylate (GMA) by reversible addition−fragmentation chain transfer polymerization (RAFT) in dimethylformamide to produce a P(GMA 62 ‐ stat ‐(MAm‐GFF) 7 ) macromolecular chain transfer agent (macro‐CTA). This peptide‐containing macro‐CTA is then successfully chain‐extended with poly(2‐hydroxypropyl methacrylate) (PHPMA) by aqueous dispersion PISA, forming P(GMA 62 ‐ stat ‐(MAm‐GFF) 7 )‐ b ‐PHPMA 27 self‐assembled objects. The impacts of temperature and monomer conversion on the morphologies formed during the PISA process are investigated by analyzing samples withdrawn at different time during the polymerization of HPMA using transmission electron microscopy (TEM) and dynamic light scattering (DLS) at different temperatures (5–70 °C).