Street vending business and urbanization coexist in cities of most of the third world countries Tanzania being no exception. As one of the fast growing African cities, Dar es Salaam is estimated to be inhabited by a total of 700,000 both mobile and fixed street vendors. Due to limited formal employment, a substantial number of Tanzanian youths are engaged in small scale businesses which provide a legally accepted means of survival. Spatial expansion of the city needs to be observed on how it matches with expansion of street vending business, thus unveiling the relationship between the duo. An obvious explanation to this would be the presence of a “new market‟ catering for “unmet needs” facilitated by the growing population with new market demand. This paper, therefore, seeks to establish the relationship between the changing nature and character of street vending with spatial variation within the urban and peri-urban settings. The findings may be useful in ascertaining the interplay between street vending activities on urbanization and vice versa. Three indicators are, in this case, used in establishing the causation based on survey results. While urbanization is traced by the people’s involvement in agriculture, and distance from the city centre; characteristics of street vending business were studied basing on nature of products sold and the source areas of the products. Both quantitative and qualitative approaches were used for concluding the findings. Data were collected around 10 centres along Morogoro Road from the Kimara bus stop located 15 km to Mlandizi, 65 km from the city centre, using 100 semi-structured questionnaires and 10 interview guides. Descriptive statistics and grounded theory were deployed. The major finding indicated that there is causation between street vending characteristics and urbanization demonstrated by the observed positive correlation between various products sold and involvement or non-involvement in farming activities.