Growth of Penicillium brevicompactum was examined on five solid media. Fungal growth was established by diameter measurements up to 50 days. Seventy experimental curves were fitted by Baranyi's primary predictive model. The growth rates were then analysed by non-parametric statistical methods. Penicillium brevicompactum could colonize the surface of solid media containing up to 700 g l−1 of sugar (50% glucose—50% fructose) with a growth rate of 0·9 mm day−1 (median values). Fitting curves by non-linear models followed by a non-parametric multiple comparison seems to be a convenient method for detecting differences in fungal growth on solid media. These two methods would be useful for studying fungal spoilage of bakery products with intermediate water activity.