The present invention relates to nucleic acids of the general formula (I): (N u G l X m G n N v ) a and derivatives thereof as an immunostimulating agent/adjuvant and to compositions containing same, optionally comprising an additional adjuvant. The present invention furthermore relates to a pharmaceutical composition or to a vaccine, each containing nucleic acids of formula (I) above and/or derivatives thereof as an immunostimulating agent, and optionally at least one additional pharmaceutically active component, e.g. an antigenic agent. The present invention relates likewise to the use of the pharmaceutical composition or of the vaccine for the treatment of cancer diseases, infectious diseases, allergies and autoimmune diseases etc. Likewise, the present invention includes the use of nucleic acids of the general formula (I): (N u G l X m G n N v ) a and/or derivatives thereof for the preparation of a pharmaceutical composition for the treatment of such diseases.