The quality of the online resources for parents offering access to open knowledge has hardly received attention despite their increasing number. This paper provides a framework to examine the ethical and content quality of parenting resources. The ethical criteria were based on "the Health on the Net" (HON) framework whereas the content criteria were based on the Positive Parenting framework and the effectiveness of the learning materials used. The criteria were applied to a survey of international websites (n = 100) for Spanish-speaking parents. Chi-square analyses showed that websites from Spain, official companies sites and information sites, as compared to South American, parents' and interactive sites, scored higher in the ethical criteria of privacy, authority, justifiability and financial disclosure. Hierarchical cluster analysis applied to content criteria showed that the High quality websites, unlike the Low quality ones, valued gender equality, a positive parental role, modeled a variety of parenting practices, educational contents with multimedia formats, and made use of experiential, academic and technical information. Privacy, financial disclosure and justifiability were more likely to be found in the High and Medium quality content clusters. In conclusion, the study illustrates some of the challenges of open knowledge and sets out the priority areas for quality improvement for website designers and for professionals who want to help parents develop effective skills for searching for trustworthy sources.