FROM Dermatology Department of Tanta University Hospitals during 2016, it was observed that cutaneous fungal infections were more common in patients dealing with indoor closed pipe networks as a water source (recorded in 73 cases), sewage disposal by outdoor conservancy (68 cases), of 2-20 years old (38 cases) and house wives (23 cases). The most common fungal isolates among the studied cutaneous infections were Microsporum canis (21 cases), Malassezia furfur (16 cases), Trichophyton rubrum (11 cases), Candida albicans (9 cases), Epidermophyton floccosum (8 cases) and Candida tropicalis (7 cases); that caused Tinea capitis (29 cases), Tinea unguium (23 cases), Tinea versicolor (16 cases) and Tinea corporis (13 cases). The present study reported an eco-friendly biosynthesis of stable silver nano-particles (AgNPs) by two selected marine algal extracts; which gave a great antifungal activity against the most commonly isolated fungi; that was confirmed by their low MIC values, namely MIC for AgNPs of Corallina mediterranea was 0.25mg/ml against Epidermophyton floccosum, while MIC for AgNPs of C. officinalis was 0.5mg/ml against Candida tropicalis and further elucidated by their destructive effects, as observable thinning of cell wall (as low as 89.1nm in C. tropicalis and 54.9nm in E. floccosum), agglutination of cellular proteins, rupture of cell membrane and leakage of intracellular components, revealed through TEM examinations.