The first quantitative experimental results are presented on homogeneous nucleation and droplet growth in a multicomponent gas-vapor mixture. Using the pulse-expansion wave tube technique, we investigated the condensation behavior of natural gas consisting of over 30 components. Data were obtained in the pressure range between 6 and 24 bar and at temperatures ranging from 221 to 237 K. The observed droplet growth rates are quantitatively explained using a multicomponent model for diffusion controlled growth. The nucleation rate data are for the moment mainly presented as a challenge to theoreticians, although some qualitative arguments are presented that could be helpful in the interpretation. The data appear to agree at least qualitatively...