N-(2-Hydroxypropyl)methacrylamide polymer precursors (pHPMA) with very narrow distribution of molecular weights and polymer chain terminating in a single reactive group have big potential in the synthesis of various polymer drug and gene delivery systems. This paper shows that pHPMA can be prepared by reversible addition-fragmentation chain transfer (RAFT) polymerization; the pHPMAs prepared by RAFT polymerization conducted to high conversions contained at the alpha-end of the polymer chain a single functional group originated from both, the chain transfer agent (CTA) and initiator (INI) in ratio depending on polymerization conditions. The well-defined monofunctional pHPMAs with narrow molecular weight distribution and with single reactive group situated at the alpha-polymer chain end can be prepared in one step by RAFT polymerization initiated by the tailor-made CTA and INI, both containing the same functional group in their structure. Synthesis of pHPMAs terminating in various reactive groups (azide, propargyl, thiazolidin-2-thione, amino, hydrazide) was also described.