The aim of this comparative cross-sectional study was to assess neurocognitive impairment, haematological findings, and clinical symptoms of lead exposure among 316 male battery plant workers aged between 20 and 61 years. Compared to 123 matched controls (matching in age and years of work), the exposed workers showed significantly higher mean blood lead level (BLL) and lower haematocrit, haemoglobin, and red blood cell count. Mean BLL significantly correlated with clinical symptoms such as nocturia, increased urination frequency, oedema, drop in deep tendon reflex, concentration impairment, agitation, headache, depression, abdominal pain, palpitation, fatigue, and diminished sex drive. Workers with clinical disorders had higher BLL and lower haematological parameters. These findings warn that silent toxicological problems caused by lead might go unnoticed by health professionals.