Current farming of European sea bass and gilthead sea bream, as in other finfish farming activities, involves facilities where large numbers of fish are kept together for a relatively long period of time. In hatcheries and land-based pre-growth systems using open or close-cycle water supply, millions of larvae and juveniles are packed for few months before being transferred to the open cages. There, a high number of grown animals (occasionally 100.000-500.000 per cage) are struggling for survival against several stressors for 12-15 months. Therefore, disease outbreaks are inevitable and they can become a serious risk if farm management is inadequate. Infectious diseases in caged farming may become a substantial problem not only via substantial extra financial costs due to mortalities, decrease of the performance of the fish and therapeutic costs but also due to depreciation of product value and welfare issues. This particular issue was clearly identified in PerformFISH and this is the reason why antibacterial and antiparasitic medicines have been particularly addressed in Task 3.4: Medicines, Biocides and Bioactive Substances of the WP3 (Boosting Fish Health at all Lifecycle Stages) and particularly in the subtasks Task 3.4.1: Medicines: Current Use and Task 3.4.2: Developing Future Treatments. Among the potential disease agents, bacterial pathogens are the most frequently diagnosed. Pathogens are among the main limiting factors of the aquaculture industry, as they can produce financial losses estimated to be about 20% of the total production value. Among them, it is estimated that the world annual grow-out loss due to parasites in finfish farming ranges from 1% to 10% of harvest size, with an annual cost that can reach up to $9.58 billion (Shin et al., 2015). The main objective of this document is to present the current knowledge on therapeutic and control measures for the most relevant parasitic diseases in European sea bass and gilthead sea bream. This study covers the knowledge on basic preliminary information from limited laboratory experiments in these two fish species, information from other similar fish species or from differing fish species (mainly from salmon) harbouring parasites of similar taxonomic groups, that can be applied to Mediterranean fish farming. Current parasite therapeutic and control practices is also presented. The final aim is to provide the Mediterranean fish farming industry with updated information, and also with relevant information about potential and available parasite control strategies, each one with details about their strengths, problems, applicability and concerns and also future clues, so the industry specialists can run a benchmarking exercise in order to evaluate the most suitable methods and strategies to be implemented in the future. These future selected strategies can be considered as “new tools” for parasite control and can be implemented and eventually validated in the PerformFISH WP6: Testing and Validation: Combining promising solutions, technologies and testing in industrial settings.