The Yemen Arab Republic is divided into four main areas according to the climatic conditions. These areas are the coastal plains, the foothills and midlands, the central highlands and the eastern areas. A range of crops are grown in these areas using traditional agricultural methods. Yields are low and disease is one of the factors affecting them. Surveys of economically important diseases have previously been undertaken and the results of these together with a survey carried out by the authors during the period June 1976 – June 1978 are presented. A revised list of plant diseases for several crops is given and includes new, previously unpublished records.