Increasing piglet survival remains a priority for pig producers. In breeding programs, it can be increased by considering piglet maturity at birth, defined as the level of full development. An immature piglet is less likely to survive the first few days after birth. A morphological trait that can help to characterize a severe immaturity is the shape of the head (Maturity_obs) with initially 3 levels, S for severe immaturity, L for light (mild) immaturity, N for normal. This dataset corresponds to the sample information of all animals, piglet neonates, used to develop the prediction model (PicLet project) with training or test samples (Farms 3 to 5). These neonates are of 3 genotypes (GT); Large White (LW), Landrace (LR), and crossed LRLW. This dataset also includes information on completely independent samples from another project (SuBPig) used to investigate the relevance of the prediction model on newborn piglets of different genotypes and from different farms (Farm 1 and Farm 2). The genotypes of the SuBPig piglets are LW and two divergent genetic lines for residual feed intake (RFI) with LRFI line sows (low RFI, more efficient animals in terms of RFI) and three HRFI line sows (high RFI, less efficient).