The treatment of 40,000 seeds of narrow-leafed sweet lupin (Lupinus angustifolius), cv. 'Boruta' with ethyl methanesulfonate (EMS) resulted in about 20,000 M 2 lines. A first series of 2,000 M 2 lines were grown in 2007 to be examined for aberrant plants. Several kinds of characters were considered, e.g. leaf shape, leaf colour, plant vigour, branching type, flower colour. Seeds were obtained from 1,438 aberrant plants displaying alterations in one to four visually assessed traits. Some combinations of altered traits coincided with altered seed numbers per plant. In 2008 666 M 3 lines were grown in the field to check heritability of the alterations observed in generation M 2 . Of the M 3 lines, 520 were homogeneous for the mutated traits or trait combinations. Some of the lines are described and discussed regarding their potential for improving the agronomic value of narrow-leafed lupin as a crop.