The Solitary Tinamou (Tinamus solitarius) is endemic to the Atlantic Forest. Little information is available about this bird species because of its low conservation priority and cryptic habits. Hunting and habitat loss are the main threats to the species, which is regionally threatened in southern and southeastern Brazil. We used camera traps installed along unpaved roads, at edges with roads, and in the forest interior in one of the last large remnants of the lowland Brazilian Atlantic Forest in southeastern Brazil to determine daily and seasonal activity patterns of the Solitary Tinamou. We obtained 256 records between June 2005 and December 2013 (sampling effort = 14,316 cameras-day). Solitary Tinamous were mainly observed away from roads, confirming the tendency of the species to occur more frequently in areas with greater canopy cover. Our data confirmed that photoperiod may influence daily activity patterns of the Solitary Tinamou, as the duration of daylight differs among the seasons. The species showed a total of 16 hrs of daily activity during the wet season with two main activity peaks during the day (0500 and 1800) and an intervening smaller peak (1300). During the dry season, the species showed a shorter duration of daily activity (13 hrs), and the activity peaks occurred either 2 hrs later or 1 hr earlier. Despite the difference in daily activity patterns between seasons, the number of records obtained was proportional to the sampling effort at each season, and the records were not correlated with climatic variables. The species was most often recorded between August and January, a time span that coincided with its reproductive period. It was less often recorded between March and May, a finding that could be related to the timing of the post-nuptial molting period. Our data serve to enhance current knowledge of activity patterns of T. solitarius and may be used in future studies relating temporal niche partitioning by the Solitary Tinamou with other frugivores or between the species and its predators.