The miniemulsion process has been applied for the preparation of poly(n-butylcyanoacrylate) (PBCA) nanoparticles. In the first step a miniemulsion is prepared from n-butylcyanoacrylate in hydrochloric acid solution using sodium dodecyl sulfate as surfactant. In the second step, a base solution is added to initiate polymerization, and the polymeric particles are formed. Using amines or amino acids as initiators allowed the convenient functionalization of the polymer particles' surface. The influence of surfactant concentration and sonication time on particle size and size distribution has been studied as well as the influence of pH, concentration, and amount of initiator on the particle size and the distribution of the molar mass of the polymer. The detected pH dependence of the particles' zeta potential shows the presence of carboxyl groups on the particles' surface after the initiation with amino acids. GPC and NMR measurements indicate a covalent bonding of the amino acid to the polymer.