Background: One aspect of idiopathic normal pressure hydrocephalus (iNPH) that has garnered interest is whether it can be familial. Thus far, the literature consists of several case reports, and two larger pedigree cohorts. Our objective is to highlight key deficiencies in such studies so far, illustrating them through a family case study of our own, and to propose a set of criteria that studies on familial iNPH should incorporate. Methods: Our case study is a retrospective chart review of three siblings, two male and one female, who were diagnosed with iNPH after the age of 60, and whose symptoms improved with cerebrospinal fluid (CSF) shunting. An interview with them revealed that their mother also exhibited symptoms of iNPH, but was never treated with a shunt. Results: Our family case is reflective of several deficiencies of familial iNPH research as a whole—unconfirmed diagnosis, especially confirmation with shunt responsiveness, and lack of measures of symptom improvement. Conclusions: Research on familial iNPH should focus on patients whose diagnosis is confirmed by shunt responsiveness, and should involve a system to objectively measure signs of NPH. Studies should also compare the prevalence of iNPH among first degree relatives of NPH patients to that in the general population.