We have synthesized and studied the biological and biophysical properties of triazole-linked ribo and xylo locked nucleic acid (LNA). The combination of LNA with the Isobe triazole linkage gave high binding affinity when incorporated at the 3' or 5' termini of oligonucleotides, but low binding affinity at internal positions. Antisense oligonucleotides (ASOs) and siRNAs containing triazole dimers were highly active and nuclease resistant. Surprisingly, the xyloLNA-modified siRNA was the most active of the series.