Dendritic polycation (PG‐BEN) using polyglycerol as a core and secondary amine shell consisting of N¹,N¹¹‐bisethylnorspermine (BEN) was synthesized. Polymers containing primary amines in the shell (PG‐Nor and PG‐NH₂) were synthesized as controls to allow evaluation of the shell effect on physicochemical and transfection properties of the polymers. All studied polymers condensed DNA and formed polyplexes with sizes less than 110 nm. PG‐BEN and PG‐Nor had a similar transfection activity that was fully comparable with that of the control polyethylenimine. Amongst the studied polymers, PG‐BEN demonstrated the lowest cytotoxicity, suggesting that PG‐BEN is a promising gene delivery vector with favorable transfection/toxicity profile. Copyright © 2014 John Wiley & Sons, Ltd.