Ultrasound was introduced in the 1970s as a method to detect schistosomal pathology both at hospital and field level. It has since been established as a safe, rapid, non-invasive and relatively inexpensive technique for assessing schistosomiasis-related lesions in individual patients and in community surveys. It can be used to validate laboratory tests to measure morbidity and provides an opportunity to visualize the evolution of pathological lesions after treatment. The interpretation of ultrasound imaging depends on the experience of the investigators and it may not be the ideal tool to detect early lesions of the affected organs. This paper reviews and critically discusses the present knowledge of morbidity due to the different types of schistosomiasis as it can be observed using ultrasound, with special reference to its use as a diagnostic and monitoring tool in field surveys. It analyses the practical use, benefits and drawbacks of ultrasound investigations to assess pathological lesions due to schistosomiasis in relation to other diagnostic tools. The role of ultrasound investigations among other monitoring approaches in control programmes is discussed in the context of rational control strategies.