With up to 80% of pregnant women experiencing nausea and vomiting of pregnancy (NVP), it is critical to have a graded scale of its severity as a guide for appropriate treatment. In 2002 we introduced the Pregnancy-Unique Quantification of Emesis (PUQE) scoring system, which assessed the severity of nausea and vomiting in pregnancy (NVP) based on three physical symptoms: nausea, vomiting, and retching over the previous 12 hours. We present here validation of an extension of the original PUQE, by assessing NVP over 24 hours. This extension is deemed more clinically relevant, because assessment of symptoms over only 12 hours may encompass sleeping hours and hence may not adequately capture the length and severity of the symptoms. In this study we assessed the external validity of the new PUQE-24 by examining its ability to evaluate several characteristics associated with NVP: (a) ability to take multivitamin supplements; (b) rates of hospitalization and emergency room visits for severe symptoms; (c) sleep patterns; (d) liquid intake; and (e) the woman's self-rated well-being scores. Data collected prospectively from 315 women counselled via the Motherisk NVP line were used for the validation. PUQE-24 showed strong correlation with all parameters examined except for sleep patterns and hydration status. The well-being score, however, correlated significantly with hydration status. Capturing 24 hours rather than 12 hours of symptoms may better direct management of NVP and predict its outcome.