This chapter outlines the clinical approaches for alopecic patients that are reliable in practice. We discuss three different categories of hair evaluation options: invasive methods (biopsy), semi-invasive methods (trichogram) and noninvasive methods. Besides describing the current status of diagnosis and quantification of alopecia, the chapter provides an objective assessment of these investigation tools: detailed medical history collection by structured interview and questionnaires, clinical examination of the scalp and other hair-bearing areas, laboratory investigations, assessment of hair loss distribution (patterned/diffuse/focal), dermoscopic evaluation, assessment of alopecia severity (by pull test, hair part width, counting hair test), common scales for hair loss staging, photography of alopecic areas, biopsy, trichogram, unit area trichogram, tug test, hair mount and microscopic evaluation, electron microscopy, hair card test, hair weight determination, hair densitometry, mechanical test of hair quality and computed hair analysis. Unfortunately, the disadvantages of most of these methods generate a lack of use in clinical practice, leading to few reliable evaluation methods for patients suffering from alopecia. We underline the necessity of easy, refined and precise evaluation tools for the assessment of alopecia patients.