We present the polarization analysis of a sample of 49 long-period pulsars, whose spin periods range from a few hundred milliseconds to about two and a half seconds. They were all discovered during the mid-latitude part of the HTRU survey (Keith et al. 2010MNRAS.409..619K; Bates et al. 2012MNRAS.427.1052B) apart from PSR J1846-4249 (that has been discovered in the high latitude survey and it will be presented in one of the next papers of the HTRU series). <P />After discovery and confirmation, the pulsars were followed-up with the third Parkes Digital Filterbank, observing them for at least one year to allow the determination of a complete timing solution. (2 data files).