In 1990, the worldwide accepted Shackleton  method, which provides a possibility of determining the steroid metabolites from urine, was adopted in our laboratory. The procedure is very useful in the diagnosis of different endocrine diseases and in the recognition of dysfunction or absence of enzymes with an important role in steroid metabolism, and it gives possibility to control the treatment in patients with these diseases. Besides the proximate clinical application, the method gives a convenient tool to study the steroid background of these disorders, helping us understand the mechanism of their development. In the last few years, we have examined the steroid profile of patients with hair (androgen alopecia /AA/, effluvium /E/), psychiatric problems (major depression /MD/, eating disorders /EDS/, especially anorexia nervosa and bulimia) and osteoporosis (OP). In all of the examined hair loss diseases, the levels of main androgen metabolites were increased, and elevated 5α-reductase activity were found. We could observe the alteration of the activity of 11β-hydroxysteroid dehydrogenase (11β-HSD) enzyme and marked gender differences in the changes of the steroid metabolism in patients with major depression (MD). In women with OP, the significantly decreased level of certain metabolites points to the role of testosterone, androstenedione and DHEA in postmenopausal bone loss in women. Our experiences contribute to the knowledge of the nature and steroid background of some endocrine and psychiatric diseases.