Some recent results on laser spectroscopy experiments of three-body antiprotonic helium atoms carried out at the Antiproton Decelerator facility of CERN, and pionic helium atoms carried out at the 590 MeV ring cyclotron facility of the Paul Scherrer Institute are reviewed. An infrared laser transition $(n,\ell)=(17,16)$$\rightarrow$$(17,15)$ of pionic helium at a frequency of $\nu\approx 183760$ GHz was detected.