The frequency of requests directed towards the Louisiana Office of Public Health for accurate estimates of the number of infected persons and for projections of future AIDS cases has increased over the past few years as intervention programs develop. A simple version of back-calculation, provided by Brookmeyer and Gail, was used in order to obtain such estimates for the state. Due to the limitations of HIV sero-prevalence surveys, Brookmeyer and Gail's method may provide a more inclusive estimate of infection in the local population The method requires accurate AIDS count data and an estimate of the incubation period distribution. AIDS count data was obtained from the Louisiana HIV/AIDS surveillance program. Nine different incubation period distributions estimated from various cohort studies were used in order to examine the sensitivity of the technique The technique was applied to the following sub-groups of Louisiana's population: gender, racial, exposure category, age group, and region of residence. Resulting point estimates of live HIV infected adult/adolescents varied depending on the incubation period distribution used. Ranges based on the 95% CI of the new infections for both the estimates of HIV infections and AIDS case projections were relatively large. As a means to validate the method point estimates of HIV infection among females aged 14-49 were compared to HIV prevalence from the state's child-bearing women sero-prevalence survey. The modelled rate and the observed rate were statistically similar Uncertainties addressed with the simple technique were the lack of knowledge concerning the incubation period distribution and its stability, underreporting and delay in reporting of AIDS cases, the shape of the HIV infection curve, limited knowledge of recent HIV infection rates, and interpretation of the estimates given the large ranges. Feasibility of using the technique at the local health department was also addressed. Recommendations included using the simple method as a means for obtaining crude estimates of infection rates and future AIDS incidence, the need for constructing plausible ranges around such estimates, the need for further research in the estimation of the incubation period between infection and AIDS diagnosis, and the development of more accurate techniques which may be used to obtain such estimates