Food-borne illness is a major international problem which is mainly caused due to reduced economic growth. Most commonly, street food provides source of affordable nutrients to the majority of people particularly the low income group in developing countries. Loads of micro-organisms in these food associated with the type of ingredients used, surroundings of food preparation etc. This study was carried out especially in Kathmandu Valley where the rate of consumption was very high. Isolation of micro-organisms from these food was main focus of study. Staphylococcus aureus is regarded as most common food poisoning organism so its antibiotic susceptibility and growth in varying salt concentration was specific objective of study. This book precisely focus on microbiological analysis of food along with its effect on general people.