Free polyamines and their acetylated derivatives, [putrescine (Put), spermine (Spm), spermidine (Spd), N1-acetylspermidine N1-AcSpd), N8-acetylspermidine N8-AcSpd)], were separated using ion-pair reversed-phase liquid chromatography after pre-column derivatization with dansyl chloride. Also 1,6-hexanediamine (1,6-Hda) and 1,7-diaminoheptane (1,7-Dah) which used as an internal standards were separated under the same chromatographic conditions. The reported method provided a good resolution between N1-AcSpd and N8 AcSpd (Rs = 0.86). This quality of resolution together with the very low detection limit obtained, (33.6, 8.33, 2.72, 2.67, 4.76, 4.27, and 2.27 fmoles/microliters for N1-AcSpd, N8-AcSpd, Put, 1,6-Hda, 1,7-Dah, Spm, and Spd, respectively), offer advantages to this method. Furthermore, a significant correlation coefficients were obtained as follows: 0.998 (N8-AcSpd), 0.996 N1-AcSpd), 0.997 (Put), 0.9995 (1,6-Hda), 0.9992 (1,7-Dah), 0.9996 (Spd), and 0.997 (Spm). The described method can be adapted for the separation of the free and acetylated polyamines in biological specimens.