The α-decay spectrum of 237Np was measured with a semiconductor spectrometer of 18 keV effective resolution (FWHM). Over 13 new lines were identified. The γ-ray spectrum of 237Np and 233Th from 20 to 1000 keV was studied with high-resolution Ge(Li) and Si(Li) detectors. From these data and previous results, a more complete level scheme of 233Pa is constructed. Nilsson assignments 1 2-(530), 3 2+(651) and 5 2+(642) for rotational bands based on levels at 0, 86.6 and 237.7 keV are confirmed. A new 1 2+(660) band whose lowest member is the level at 170.3 keV is identified and new levels with probable vibrational character are studied. © 1969.