As part of the science demonstration phase of the Herschel mission of the Gould Belt key program, the Aquila rift molecular complex has been observed. The complete similar to 3.3 degrees x 3.3 degrees imaging with SPIRE 250/350/500 mu m and PACS 70/160 mu m allows a deep investigation of embedded protostellar phases, probing of the dust emission from warm inner regions at 70 and 160 mu m to the bulk of the cold envelopes between 250 and 500 mu m. We used a systematic detection technique operating simultaneously on all Herschel bands to build a sample of protostars. Spectral energy distributions are derived to measure luminosities and envelope masses, and to place the protostars in an M-env-L-bol evolutionary diagram. The spatial distribution of protostars indicates three star-forming sites in Aquila, with W40/Sh2-64 HII region by far the richest. Most of the detected protostars are newly discovered. For a reduced area around the Serpens South cluster, we could compare the Herschel census of protostars with Spitzer results. The Herschel protostars are younger than in Spitzer with 7 Class 0 YSOs newly revealed by Herschel. For the entire Aquila field, we find a total of similar to 45-60 Class 0 YSOs discovered by Herschel. This confirms the global statistics of several hundred Class 0 YSOs that should be found in the whole Gould Belt Survey.