Cultural differences and bilingualism should not stand as obstacles in the intellectual and linguistic growth, as well as the social and the psychological potential, of bilingual children. So, the aim of the present study was the construction and the application of an intervention programme for the developmental speech problems of a bilingual, eight-year-old child. Moreover, the intervention intended for the improvement of his speech development and especially the enrichment of his vocabulary. The construction of the intervention programme was based on the scheduled treatment and the mnemonic improvement strategy, using the step-by-step evaluation as feedback for reconstruction of the next sessions. The intervention that could be applied by a teacher without special training was considered quite effective and should be able to further develop with some improvements.