A study was conducted to determine the spatial and temporal spread of cassava brown streak disease (CBSD) in fieldgrown cassava at Chambezi, coastal Tanzania from 2012 to 2013. The experiment was established using CBSD-free tissue culture plants of a susceptible cassava cultivar Albert. Treatments included RT-PCR tested CBSD-affected plants of field collected cultivar Albert, that were planted in three patterns: inocula centrally placed (IC), inocula diagonally placed (ID) and inocula placed in outer rows (IO) to serve as sources of disease infection. The control plots were planted with CBSD-free plants of Albert. A randomised complete block design (RCBD) with three replications was used. Data were collected monthly on CBSD foliar and stem incidence and symptom severity as well as whitefly (Bemisia tabaci) populations for six months. Representative CBSD-symptomatic leaf samples were collected for laboratory analysis using standard protocols to confirm the presence of CBSVs. The results show that treatments on foliar and stem incidence of CBSD were less effective. However, the effect of time on foliar and stem incidence was significant (P < 0.001) as expected. In addition, the effect of treatments and time (MAP) were significant (P ≤ 0.05) for CBSD symptom severity and whitefly populations. Results suggest that external inocula of CBSD-affected cassava plants in the breeding blocks at the station may have served as the main source of new infections into the experimental plots. The high rate of spread of CBSD into the experimental plots was probably also enhanced by the short distances between the experiment and the surrounding environment.