Chlorotoxin (CTX) is an established blocker of small‑conductance Cl‑ channels and has previously been demonstrated to inhibit the invasion of glioma cells. Buthus martensii Karsch chlorotoxin‑like toxin (BmK CT) is the first chlorotoxin-like peptide. The present study aimed to determine the inhibitory effect of BmK CT on the invasive ability of glioma cells, using a Transwell assay. BmK CT was subsequently radiolabeled with radionuclide 125I and its activity was compared with BmK CT. Additionally, the underlying anti‑invasive mechanism of BmK CT and 125I‑BmK CT on glioma cells was investigated by ELISA and reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR). It was revealed that BmK CT and 125I‑BmK CT were able to inhibit the invasion of glioma cells and that 125I‑BmK CT was superior to BmK CT. Consistent with the results of the Transwell assay, matrix metalloproteinase‑2 (MMP‑2) secretion by glioma cells was significantly reduced following treatment with BmK CT or 125I‑BmK CT (P<0.05). However, no significant differences in MMP-2 mRNA expression levels were identified by RT‑qPCR (P>0.05). In conclusion, the present study demonstrated that BmK CT and 125I‑BmK CT reduced the invasion of glioma cells via downregulation of MMP-2 expression. However, inhibition of the invasion of glioma cells was not demonstrated at the mRNA level.