Purpose: Our study aims at observing the consideration given to sex and gender (S/G) in head and neck cancer (HNC) studies. Since Human papilloma virus (HPV) infection is an important risk factor in a subset of HNC, we also searched for mention of HPV in this specific subset, namely the oral cavity, larynx and oropharynx. Method: We investigated the inclusion of sex and/or gender in HNC studies on ClinicalTrials.gov (AACT), collecting data up to 12 April 2022. Categorical variables were summarised with frequencies and percentages. Differences between groups were tested using Pearson’s Chi-square test or Fisher’s test for categorical variables. Results: We identified 1672 ClinicalTrials.gov registered HNC studies that were not withdrawn or terminated, which admitted all sexes: 640 (38%) explicitly addressed S/G solely as a recruitment criterion and only 89 (5%) mention S/G as a planned analytical variable. Proportionally more observational/patient registry studies treated S/G as an analytical variable than interventional studies (10% vs 5%, P-value ≤0.001). In proportion S/G mention as analytical variable was different for samples below and above 100 units (P-value ≤0.001): 8% of the studies involved more than 100 subjects and 5% less than 100 subjects. There was a significant difference between the S/G role in different interventional study phases (P-value≤0.001), the highest percentage of studies that mentioned S/G as an analytical variable was observed in interventional studies where phase was not applicable (7%) such as pilot, feasibility, and diagnostic studies. Studies involving oral cavity-oropharynx and larynx were significantly more when with samples above 100 units than other head and neck studies (38% vs 25%, P-value=0.002). HPV was mentioned in 18% of oral cavity-oropharynx studies and there was no statistically significant difference between the mention of HPV in studies concerning oral cavity-oropharynx (P-value=0.4) and other head and neck studies. Conclusion: Our analysis shows that, although fundamental, in studies concerning HNC the S/G variable is often not taken into consideration. In particular, interventional studies do not regularly account for S/G during planning of the HNC study design. We need to change this attitude to best imbue science and medicine with the proper biology and cultural differences.