First lactamimide monomers were synthesised by the bisimide-lactam ring contraction and polymerised by the high-temperature transesterification in the melt to give lactamimide-containing polymers. The polymers were amorphous with good film-forming properties, soluble in common organic solvents, and showed from low to medium molecular weight. Lactamimide-containing polymers bearing aliphatic spacers showed strong fluorescence with large Stokes shift (140-150 nm) peaking at 580-585 nm while those with phenyl groups on nitrogen atoms presented very weak fluorescence probably resulting from loose-bolt quenching, peaking at 610-615 nm. The polymers showed third-order non-linear optical susceptibility in the range of 10(-10)-10(-11) e.s.u.