Disclosed is a process for the production of lepidocrosite, which comprises the step of adding an alkali to an aqueous solution of ferrous chloride in an amount 0.20 to 0.95 times the theoretical amount necessary for converting the ferrous chloride to ferrous hydroxide, the step of blowing an oxygen-containing gas into the obtained Fe²⁺-containing solution to form a seed crystal of γ-FeOOH, the step of aging and growing γ-FeOOH while maintaining the Fe²⁺-containing solution at a pH value of 2.0 to 8.0 in a non-oxidizing atmosphere, and the step of separating grown particles of γ-FeOOH from the Fe²⁺-containing solution without addition of an oxygen-containing gas and an alkali, and washing the separated particles. According to this process, lepidocrosite having a sharp particle size distribution (uniform particle size) without agglom­eration can be obtained.