: Amelogenesis imperfecta (AI) is an overarching term for a group of rare inherited disorders of hard tooth tissues. It is characterized by various defects in proper enamel formation. AI is a severe disorder that affects both the aesthetics and function of the dentition, with affected teeth increasingly suffering from dental caries. Therefore, early diagnosis and lifelong stomatological interventions are important. Due to the complex nature of AI family history, stomatological, radiographic, and molecular genetic examinations should be part of the diagnostic portfolio. Additionally, we utilized new visualization methods for the assessment of teeth demineralization. We present a case report of two affected Czech sisters (6 and 8 years old) with clinically defined AI. These are the first Czech cases in which comprehensive clinical and genetic analysis had been carried out and reflect the complex clinical nature, positive treatment options, and limitations of candidate-gene molecular genetic testing.