The present research paper aims to study the biodiversity of macro-benthic invertebrates caught by bottom trawl nets along the eastern 180 km of the Egyptian Mediterranean coast. A total of 21 hauls were collected seasonally from July 2017 to May 2018. A total of 10765 individuals representing 118 taxa were collected during the study, affiliated with eight phyla. The maximum diversity (70 taxa) was recorded in spring; meanwhile, the highest abundance (3856 individuals) was registered in winter. Mollusca was the most diverse phylum with 46 species, while Arthropoda was the most dominant, constituting 87.89% of the total amount of benthos. The stomatopod Erugosquilla massavensis was the most prevalent species (about 41.8% of total benthos). Of the 118 recorded taxa, 11 species were regarded as new records in the Egyptian Mediterranean Sea. The maximum diversity index value (Hˊ=2.81) was estimated for haul 10 (autumn); meanwhile, a minimum value of (0.26) was estimated for haul 15 (winter). Excluding the 10 taxa identified at the genus level, there were 71 indigenous species (66%). In contrast, alien, or non-indigenous species (NIS) contributed a relatively high number (37 species), constituting 34% of the total number of identified species. Additionally, 24.2% were of Indo-Pacific and Indian origin. So, planned comprehensive national monitoring programs for biodiversity and NIS in the study area are recommended for recording any new alien species.