Generally, 3-amino-9-ethylcarbazole is considered a versatile compound not only for its unique electronic properties but also for its significance as a building block in synthetic, pharmaceutical, and material chemistry. The synthesis, chemical reactivity, and applications of 3-amino-9-ethylcarbazole are described in this review. The presence of the amino group at position 3 exhibits a unique reactivity with both C-2 and C-4. The reactions of 3-amino-9-ethylcarbazole are divided into three categories, reactions that involve the amino group and cyclization reactions that involve the amino group and C-2 and/or C-4. In this review, relevant and appropriate applications of the synthesized, isolated, and condensed carbazole derivatives are reported.