Utilising temporal data on illness onset and specimen collection, and the epidemic curve derived from these data, we provide estimates of the transmissibility parameters of pH1N1 during the first wave experienced in South Africa. Our results focus primarily on the use of analytical techniques to estimate initial R t and SI without incorporating contact tracing or household transmission studies. However, when parameters from field studies are available, we show that these can be incorporated to provide robust estimates of transmission parameters. We found that initial R t estimates established using the likelihood-based method for the simultaneous estimation of R t and SI (method 1: initialR R t : 1.47, SI: 2.78 days) are in agreement with those obtained using SI observed in field investigations [22] (method 2: initialR R t : 1.43 and 1.49 using observed SI for laboratory confirmed or laboratory confirmed and suspected cases respectively). In addition, the mean SI estimate obtained with method 1 (2.78 days) is in agreement with field findings (SI: 2.3-2.7 days using observed SI for laboratory confirmed or laboratory confirmed and suspected cases respectively). Previous estimates of initial R t and the mean SI for pH1N1 have ranged between 1.3-2.9 and 2.5-3.3 days, respectively [2, [6] [7] [8] [9] [10] [11] [14] [15] [16] [17] [18] [19] . Our estimates are consistent with these findings, regardless of the method used for the analysis and despite difference in climate, demography and health systems across these countries. It appears that once established, the transmission characteristics of pH1N1 are very consistent. Differences in transmission rates may occur within smaller subgroups of the overall population; however, this has not been well-studied.