Primary hyperhidrosis consists of excessive focal sweating. Affected individuals camouflage the sweating on their body, avoiding stigmatisation. Hence, misrepresentation in social interactions is a common feature in patients with hyperhidrosis. The aim of this study was to investigate impostor phenomenon, perfectionism, self-compassion, stress and anxiety among individuals with primary hyperhidrosis. A cross-sectional study was conducted at our clinic among 100 participants with axillary and palmar primary hyperhidrosis. The questionnaire contained a hyperhidrosis part and Perceived Stress Scale-4, Generalised Anxiety Disorder Scale-2, Clinical Perfectionism Questionnaire-6, Self-Compassion Scale Short form and Clance Impostor Phenomenon Scale. Descriptive statistics was used for analyses of categorical variables. As data were normally distributed independent t-test and one-way analysis of variance with post hoc Tukey test were used to compare the mean values for the questionnaires with other variables. Pearson’s correlation was used, and a forward multiple linear regression model was performed to predict presence of impostor phenomenon with gender, age and other scales in this study. Impostor phenomenon occurred in almost half of our patients (48%) with hyperhidrosis. While feelings of impostor phenomenon were more common in women, there was no difference between gender regarding its intensity levels ( p = 0.07). In addition, we found a significant ( p < 0.001) negative correlation between impostor phenomenon and self-compassion, while feelings of impostoer phenomenon increased with stress, anxiety and perfectionism ( p < 0.001). Feelings of impostor phenomenon was found in 48% of individuals with hyperhidrosis which indicates that it is a common feature in this patient group. Future research is warranted regarding the prevalence of impostor phenomenon in hyperhidrosis and other medical conditions, among men and women, seeking medical healthcare. Psychological interventions in hyperhidrosis may be beneficial both for the individual and in public health, by facilitating management of patients’ daily lives and saving considerable resources in healthcare regarding pharmacological interventions and medical consultations.