A constructed wetland (CW) is an integrated and enhanced version of natural ecosystem for fate and transport of pharmaceutically active compounds (PhAC). This thesis demonstrates removal mechanisms of PhACs in CWs and their application as post-treatment processes to eliminate PhACs from wastewater effluent. Four main subjects were investigated in this thesis: First: mechanisms of PhAC removal in individual processes in CWs, including photodegradation, sorption, biodegradation, and phytoremediation and their interactions. Second: effect of important environmental factors (i.e. dissolved organic matter, redox conditions) on the removal processes. Third: enhancement of photodegradation and biodegradation capacity in CWs. And last: fate and distribution of PhACs in CWs by using chemical and toxicological analytical tools.