Heavy-chain antibodies (HCAbs) without light chains naturally exist in the blood of the Camelidae family of animals. The variable domain of HCAb, referred to as a nanobody (Nb or VHH), is currently the smallest, fully functional antigen-binding fragment. Consequently, Nbs and their further development into assembles are attractive for targeting tumors. The characteristics and generation of Nbs have already been reviewed. Here, we reviewed their novel assembles in targeted research, which may bring novel perspectives for tumor-targeted diagnosis and therapy.