AbstractPoly(Nε‐stearyl‐L‐lysine) and poly(Nε‐pelargonyl‐L‐lysine) were synthesized both by polymerization ofNε‐pelargonyl andNε‐stearyl‐L‐lysine NCA and by acylation of poly(L‐lysine) with pelargonyl and stearyl chloride. This second route has proven to be very useful, since completely acylated polymers are obtained in almost quantitative yield, whereas the usual scheme of preparation of ε protected poly(L‐lysine) cannot easily be applied due to solubility problems.Poly(Nεpelargonyl and stearyl‐L‐lysine) are soluble in alcohols containing linear aliphatic chains such asn‐butanol andn‐octanol and in mixtures of these alcohols with hydrocarbons such asn‐hexane andn‐heptane. Both polymers show an α‐helical conformation in the above solvents, which can be disrupted upon addition of sulfuric acid. Also in the solid state, poly(Nε‐stearyl‐L‐lysine) and poly(Nε‐pelargonyl‐L‐lysine)