The objective was to evaluate the effects of moisture content, type of package and environmental storage conditions on the conservation of papaya seeds (Carica papaya L.), cv. Improved Sunrise Solo Line 72/12. Seeds were removed from fruits at the ?first-ripe? stage, washed and hand-scarified to eliminate the aril. Then, they were shadow dried to 13.8; 11.4; 9.4 and 7.0% moisture content. After, chemical treatment with the fungicide Thiram, the seeds were packed using plastic (0.07mm thick) and paper bags (two paper bags each one 0,09mm thick) and stored at room temperature (means temperature and relative humidity of 25.4ºC and 80.2%) and at low temperature (2ºC a 5ºC) in the frost free refrigerator, for a period of eigth months. Seeds were taken to field tests before storage and after storage on a monthly basis and their behaviour evaluated based upon the following variables: seed moisture content, percentage and speed of emergence, seedling height, ?colon? diameter, and wet and dry matter acumulation. The percentage and speed of emergence decreased along storage. The conservation was not significantly affected by the package type, when seeds were dried to 7.0% initial moisture content and stored in the refrigerator. At room temperature, seeds with 7.0% moisture content presented lower physiological quality, suggesting that seeds with 11.4 and 9.4% moisture contents should be packed in plastic and paper bags, respectively. In general, seeds stored at low temperatures reached the hygroscopic equilibrium with lower moisture contents than those stored at room temperature.