_Smilisca_ breeds primarily in quiet water and reaches its height of breeding activity at times of plentiful rainfall,--usually from May through October. Through most of its range _Smilisca baudini_ breeds in those months, but in some places where abundant rain falls in other seasons, the species breeds at those times. For example, in southern El Peten and northern Alta Verapaz, Guatemala, _Smilisca baudini_ has been found breeding in February and March. The other pond-breeding species (_S. cyanosticta_, _phaeota_, and _puma_) live in regions lacking a prolonged dry season, and possibly they breed throughout the year, but breeding activity seems to be greatest in the rainiest months. The two stream-breeding species (_S. sila_ and _sordida_) breed in the dry season when the streams are low and clear, principally in December through April. At high elevations the species sometimes breed in the rainy season; also, individuals sometimes breed in the short dry season (summer canicula) in July and August. At several localities species have been found breeding at different times of the year: _S. baudini_ in March and July at Chinaja, Guatemala; _S. phaeota_ in April and August at Palmar Sur, Costa Rica; _S. puma_ in February and July at Puerto Viejo, Costa Rica; and _S. sila_ in February, April, and August at El Volcan, Panama. These observations indicate only that the population breeds at more than one time in the year, but do not provide any evidence on the breeding cycles of the individual frogs. This is one important aspect of the natural history of _Smilisca_ for which we lack data. _Breeding Sites_ All members of the genus _Smilisca_ presumably deposit their eggs in water. _Smilisca baudini_ usually breeds in temporary rain pools; often these are nothing more than shallow, muddy puddles. In other instances the sites are extensive ditches or large flooded areas (Pl. 8, Fig. 1). This species is an opportunistic breeder, and males gather at any of a wide variety of suitable breeding sites that are formed by torrential rains in the early part of the rainy season. _Smilisca baudini_ nearly always breeds in open pools having bare earthen edges. Frequently congregations of _S. baudini_ are found at such small pools, but are absent from nearby large ponds surrounded by vegetation. Little is known of the breeding habits of _S. cyanosticta_, which inhabits humid forests on foothills and lowlands. Apparently its breeding sites are not unlike those of _S. phaeota_, which usually are pools surrounded by vegetation (Pl. 8, Fig. 2), although sometimes males of _S. cyanosticta_ call from open muddy puddles. In uplands, where standing water is uncommon, this species breeds in quiet pools in streams. _Smilisca puma_ breeds in grass-choked ponds and marshes, where the males call from bases of dense clumps of grass in the water (Pl. 9, Fig. 1).