The main aim of the study is to study the factors influencing consumer buying behavior and consumer decision making process and know the determinants of satisfaction of consumer towards FMCG products in Tirunelveli City. The researcher has used both the primary data and secondary data in this study. Field survey method was employed to collect primary data from 450 respondents framed questionnaire is used for data collection. Secondary data were collected through various journals, magazines, reports and newspapers. For the purpose of the study 450 respondents have been chosen in Tirunelveli City by using convenience sampling technique. The questionnaire was prepared and administered in person to all the respondents. The information collected have been edited for reliability and consistency and presented in a master table for analysis. The researcher has used different statistical tools namely ANOVA, multiple regression and correlation. It is concluded that occupation, educational qualification and monthly income of the consumer is a significant factor influencing consumer buying behavior and consumer decision making process of FMCG products namely products factors, price factors, place factors and promotion factors. The study reveals that there is a significant relationship between factors influencing consumer buying behavior and consumer decision making process of FMCG products namely promotion factors and satisfaction towards FMCG products namely place of purchase or location of shops, product features, price of products, promotional factors and people’s influence to purchase.