Parasitic weeds of the families Cuscutaceae, Orobanchaceae and Scrophulariaceae are considered to be among the major problems facing agriculture in the tropics and subtropics. In the last decades, enormous efforts have been made and success achieved by scientists all over the world in gaining a better understanding of their biology and ecology as well as of control methods. However, no substantial reduction of infestation has been achieved in the past and control strategies specific to the different parasites, crops and farming systems must be further developed or adapted and realised among a wider farming population with suitable extension methods. This technical manual provides methodologies for various aspects of research and extension related to parasitic weed species of the genera Striga, Alectra, Orobanche and Cuscuta. It has the intention to support scientists and extension workers of international and national research and extension institutes and universities, who are either new to the subject or plan to apply further techniques they are not yet familiar with.