The alkaloid composition of Convolvulus lanatus was investigated by GLC and GLC-MS. Altogether, thirteen tropane and pyrrolidine alkaloids were identified on the basis of mass spectral data and/or Kovats retention indices. Twelve of them have been recorded for the first time in this plant and some of these alkaloids were identified for the first time in the genus Convolvulus. Cuscohygrine is the major constituent. Qualitative and quantitative differences of root and aerial parts are discussed.