The compound prepared by treating urea with hydrazine:[2] A further reaction can occur to give carbohydrazide: Semicarbazide is frequently reacted with aldehydes and ketones to produce semicarbazones via a condensation reaction.

This is an example of imine formation resulting from the reaction of a primary amine with a carbonyl group.

[3] Semicarbazide products (semicarbazones and thiosemicarbazones) are known to have an activity of antiviral, antiinfective and antineoplastic through binding to copper or iron in cells.

Semicarbazide is used in preparing pharmaceuticals including nitrofuran antibacterials (furazolidone, nitrofurazone, nitrofurantoin) and related compounds.

Semicarbazide stains α-keto acids on the TLC plate, which can then be viewed under ultraviolet light.