Wastewater workers are exposed to various job-related hazards. This work was carried out in the period from November, 2004 to January, 2005. All workers (one hundred and ninety two workers) in the Jeddah Municipal Wastewater Treatment Plants (MWTP) were interviewed. They were asked to answer a precoded questionnaire that included personal data and complete medical (present, past, and family) history. They were also asked about history of previous medical examinations in details. Psychological problems were the most common health problems as they formed 84.4% followed by mucous membranes' irritation which constituted 42.2%. The percentage of workers following the safety precautions: wearing anti-slide shoes; the use of personal protective tools for the protection of the skin and eyes; the use of safety precautions in mixing chemicals; the safe storage, transfer, and circulation of chemicals; and ensuring the safety of electrical appliances were 14.6%, 75%, 13.5%, 91.7%, and 95.8%, respectively. The T-test was carried out between those having mucous membrane irritation and those who didn't have mucous membrane irritation as regards the duration of work and it was found to be statistically significant (p=0.000). Those who suffered from mucous membrane irritation have mean work duration of 5.04 years whereas those without irritation have a mean of 6.75 years. Finally, t-test was carried out between those having psychological problems and those who didn't have psychological problems and it was found to be significant (p=0.007). The mean work duration for those suffering from psychological problems was 6.2 years whereas those who didn't suffer from psychological problems had a mean work duration of 5.1 years.