Research PaperTanzania is among countries which adopted and implemented an Electronic Procurement System (EPS) in their procurement operations. However, little attention has been given on technological factors that influence vendors’ participation in public electronic procurement system(PEPS). This study examined technological factors influencing vendors’ participation in PEPS. Ilala District was chosen as a study area and research design was cross-sectional. Simple Random sampling technique and purposive sampling technique were used to select300 respondents and three key informants respectively. Qualitative and Quantitative data were collected through Key Informants Interviews (KIIs) guide and structured questionnaire respectively. Structural Equation Modelling (SEM) and content analysis were used for quantitative and qualitative data analysis respectively. The study found technological factors like information transparency, creativity and innovation, data quality and management, system integration, data security; computer and IT literacy were significant at p-value<0.001. Therefore the study concluded that, technological factors have influence on the vendors’ participation in PEPS. The Study recommends to Public Procurement Regulatory Authority (PPRA) to consider oversee significant technological factors(like data management, data quality, information transparency and security)for attracting vendors to participate in the system. PPRA should maximise privacy on sensitive data and allow access by levels for operation purpose only.