This paper considers various channels of electron-positron pair, neutron, and γ-quantum generation via the ultrashort high-power laser pulse interaction with targets made from different materials. The positron yields in materials with different Z are estimated for the positron production by high-speed electrons and γ-photons. It is shown that a picosecond 100-TW laser pulse gives rise to formation of about 10 ¹⁰ positrons, possible channels of the neutron production in light-and heavy-atom materials being studied as well. It is ascertained that the formation of up to 10 ⁷ laser neutrons per shot is possible when the laser intensity is approximately 10 ²¹ W/cm ² on a heavy-atom target.