Lead encephalopathy is a rare but serious neurological complication, often underrecognised in adults. Its neuropsychiatric manifestations can closely mimic autoimmune encephalitis, posing diagnostic and therapeutic dilemmas. Reporting such cases is crucial in the Indian scenario where occupational exposures, including unregulated cosmetic products remain a public health challenge, and in the global context where lead toxicity continues to resurface in unsuspected ways. We describe a 41-year-old female beautician from Kerala who presented with progressive cognitive decline, visual hallucinations, seizures, ataxia, and raised intracranial pressure over three months. Initial clinical and radiological features suggested autoimmune encephalitis. However, negative autoimmune panels and the presence of microcytic hypochromic anaemia prompted further evaluation. Her serum lead levels were markedly elevated (72.23 µg/dL; normal <10 µg/dL), confirming lead encephalopathy secondary to chronic occupational exposure from cosmetic products. The patient was initiated on chelation therapy and provided supportive neurocritical care, along with occupational counselling to avoid further exposure. She showed gradual neurological recovery with improvement in cognition, seizure control, and gait, and was able to return to work with protective modifications. This case highlights the diagnostic complexity of adult-onset lead encephalopathy mimicking autoimmune encephalitis. In the Indian context, where occupational safety in the cosmetic industry is poorly regulated, and in the global context, where environmental toxins remain an underrecognised cause of neurological syndromes, awareness is critical.