Participation in markets is crucial for enhancing household incomes and the quality of their lives. Despite this fact, empirical information on the implications of market access and livelihood security is missing especially in Bagamoyo District. Therefore, the research was conducted in Bagamoyo District in December 2011 and January 2012, and the specific objectives were to: determine market access, identify goods and services accessed in markets, explore factors affecting market access, and determine the contribution of marketing of goods and services to households‘ livelihood security in the study area. The study population was all households living in the district. A sample size of 180 households was selected. Chi-square was used to find which factors were more associated with access to the market than other factors. It was found that availability of market information on prices of goods and services was the factor most associated with market access in the study area. The results from Chi-square test analysis indicated that there was significant association between information on prices of goods and services and access to the market places (?2=42.123; p < 0.0001). The findings on the contributions of market access to household livelihood security was tested using multiple linear regression; the findings were that the coefficient of determination, R2 was 0.344 which implies that the independent variables were able to explain about 34% of variation in the dependent variable; the other variation was due to natural errors in the model and other variables not entered in the model. Although markets are the engine of all production activities, very few market places exist. This hinders trading activities in the study area. So there is a need to make initiatives to increase access to the market.