A chronic illness in childhood has a negative impact on the paediatric patient and on family functioning. Psychological stress in parents influences the level of adjustment to the illness of their children. The Pediatric Inventory for Parents (PIP) was designed to measure stress in parents whose child has a chronic illness or requires prolonged medical monitoring. The main objective of this study is to provide a brief version of the Spanish version of the PIP, across a sample consisted of 465 main familial carers (85.2% female, n=396) between 27 and 67 years old ( =44.13; SD=5.35), of paediatric patients between 9 and 18 years old ( =12.10, SD=2.20; \u00a056.8% men, n=264) diagnosed with diabetes mellitus type I (20.9% of the sample; n=97), short stature (32.5% of the sample; n=151) or a chronic respiratory disease (asthma, cystic fibrosis, bronchiolitis obliterans and bronchiectasis) (46.6% of the sample; n=217). After performing several EFAs (Exploratory Factor Analyses) and CFAs (Confirmatory Factorial Analyses), it was decided that 30 items need to be removed. Reliability and validity results of the new 12-item version suggest appropriate psychometric properties. Cronbach\u2019s alpha value ranging between \u03b1=.42 and \u03b1=.81 and fit values obtained indicate a good fit: \u03c72\/df (88.393\/48) = 1.84 (\u03b1 < .01); S-B \u03c7\u00b2(df)= 88.393 (48); CFI=.95; IFI=.95; RMSEA=.05 (.033 - .074) for the frequency scales and \u03c72\/df (72.002\/48) = 1.5 (\u03b1 < .01); S-B\u03c7\u00b2(df)= 72.002 (48); CFI=.97; IFI=.97; RMSEA=.04 (.011 - .063) for the difficulty scales. The PIP also showed predictive ability about anxiety and depression, a positive relationship between the instrument's own scales and a negative relationship with the caregiver's age. Finally, Differences in stress levels were found depending on the paediatric patient's diagnosis. In order to facilitate the interpretation of the data, centiles were calculated for the whole sample and for each pathology separately.