The operational experience of early lagoons is outlined. The construction of a new generation of lagoons of 2000 PE to 1.000.000 PE capacity and associated practical difficulties are described. Those with innovative and space saving features treated in some detail. One includes an anaerobic baffled reactor with sludge draw-off facilities which entered service in September 1986 and which is being monitored for compliance with “Engelberg Requirements”. Cost information and space requirements for the different systems under construction are included.It is concluded that lagoon systems properly designed and sited are the most appropriate and indeed the only financially viable sewage treatment option to suit Venezuelan circumstances.