The human body contains large and small salivary glands, with the main role of secreting saliva. Saliva is a complex body fluid responsible for regulating oral flora, cleansing, moisturizing the oral cavity, digestion and numerous other vital functions. The most common specific symptom of salivary gland disease is reduced saliva secretion. Specifically, diseases affecting salivary glands are categorized as tumour and non-tumour. Non-tumour diseases include inflammatory, infectious diseases, congenital anomalies, developmental defects, autoimmune diseases and cysts. The most common causes that lead to inflammatory changes are the use of certain drugs, radiotherapy, systemic diseases, mumps virus infection, or bacterial infection with staphylococcus or streptococcus. Salivary gland tumours are rare, and in 80% of cases are found in the parotid glands. Also, benign and malignant tumours are distinguishable. The smaller the salivary gland, the higher the incidence of tumour malignancy. The treatment of the disease can vary depending on its cause. Possible therapies include surgery, symptomatic treatment such as fluid replacement, maintaining good oral hygiene, use of artificial saliva preparations or surgically supported with radiotherapy as is the case with mucoepidermoid carcinoma, the most common malignant tumour of the salivary glands.