Balea stabilis (L. Pfeiffer) collected from two localities in the Polish Carpathians were kept in the laboratory for more than four years. Observations were conducted between March and October when the snails were kept at room temperature (18–25°C); in winter they were stored at 3°C. The egg-laying period started in late March and lasted till the middle of September, with the maximum in April–May. The eggs were oval, gelatinous, with separate calcium carbonate crystals in the external envelope (average egg size 1.69 × 1.47 mm). They were deposited in batches, usually of 5–9 eggs (mean 6.9). The number of batches per snail per year was 1-7; the corresponding number of eggs – 3–41. At room temperature the incubation took 15–21 days; the hatching success was 71.9%.