Maximization of the net profit from harvesting in a one-species age-structured population is analyzed. One of the control functions is the age of harvested individuals. The constructed mathematical model is similar to vintage capital models used in economics for optimal capital replacement. The optimization technique developed by authors for the capital replacement is disseminated to the formulated problem. A qualitative analysis of the problem is provided and the interpretation of results is given. Such economic topics as a zero-investment period, optimal balanced growth, and turnpike properties are discussed. © Springer 2006.