The meeting in Trieste on physics and diagnostics of fusion-produced alpha particles was the third in a series of IAEA meetings on this topic (the first meeting was held in Kiev [1] and the second one in Aspenas [2] ). ENEA in Frascati was the general organizer of the present meeting. Local arrangements were made by the International Centre for Theoretical Physics ICTP in Trieste under the auspices of the UNESCO. The programme committee consisted of the following members: F. Engelmann (NET, CEC), M. Haegi (ENEA-EURATOM, Frascati, Italy), Ya.I. Kolesnichenko (INR, Kiev, Ukraine), S. Mahajan (ICTP, Italy), D.J. Sigmar (MIT, Cambridge, USA), K.Tani (JAERI, Naka-gun, Japan), H.Wilhelmsson (CTH-IEFT, Goteborg, Sweden). The IAEA was represented by V.V. Demchenko, and M. Haegi (ENEA) and S. Mahajan (ICTP) were responsible for the local arrangements. The meeting was attended by about 40 participants from 10 countries; 40 papers were presented. The purpose of the meeting was to discuss the current issues of physics of a-particles and other fast ions produced as a result of fusion reactions, neutral beam injection and RF-heating. The following major topics were discussed: Behaviour of fast ions in experimental devices. Alfven instabilities driven by fast ions. Ion-cyclotron emission from tokamak plasmas. Influence of sawtooth oscillations on fast ions. Ignition and thermonuclear burn. Diagnostics for a-particles. The material presented at the meeting will be published by the IAEA as a Technical Document. In addition, the journal 'Fusion Technology' (editor G. Miley) has kindly offered to produce a special issue of all, journal quality, reviewed manuscripts.