[en] This thesis describes an experimental study of the (π⁺, π⁰p) reaction at incident energy T/sub π/sup +// = 165 MeV. This work is part of the first experiment to detect neutral pions and protons in coincidence in kinematically complete measurements. The reaction was studied on ¹⁶O (using water targets) at several pion angles: θ/sub π/sup 0// = 70/degree/, 80/degree/, 110/degree/, and 130/degree/. At θ/sub π/sup 0// = 110/degree/ measurements were also made on ⁵⁶Fe, ¹²⁰Sn, and ²⁰⁸Pb. The neutral pions were detected with the LAMPF π⁰ spectrometer, while the protons were detected in a vertical array of plastic-scintillator ΔE-E telescopes, each spanning 8.5 msr. Energy spectra of the differential cross sections d⁴σ/dE/sub π/sup 0// dE/sub p/dΩ/sub π/sup 0//dΩ/sub p/ were obtained for each proton telescope and subsequently integrated over proton and pion energy and proton angle. The characteristics of these spectra are consistent with a quasi-free description of the (π⁺,π⁰p) reaction. The angular dependence of dσ/dΩ/sub π/sup 0//(θ/sub π/sup 0//) for ¹⁶O(π⁺,π⁰p) was found to be in accordance with that of the cross section for the corresponding free reaction at backward π⁰ angles. For the ¹⁶O(π⁺,π⁰p) reaction, events in which a p-shell nucleon had been removed were identified. The p-shell events were found to constitute only 40--50% of the total cross section for quasi-free one-nucleon removal. The (π⁺,π⁰p) cross section at θ/sub π/sup 0// = 110/degree/ proved to be almost the same for all target nuclei, possibly slightly decreasing as a function of A. 102 refs., 108 figs., 24 tabs