SPK is an Italian speech database of isolated and connected digits. It was designed and collected at the Istituto per la Ricerca Scientifica e Tecnologica (ITC/IRST), Trento, Italy. SPK was conceived for speaker recognition and verification purposes.With this CD-ROM, speech material corresponding to isolated digits acquired from 100 speakers (30 females and 70 males, from 23 to 50 years old) is released. Most of the speakers are from the North-East of Italy. Speech material was collected from each speaker during five recording sessions scheduled on different days. During a recording session four repetitions of the ten Italian digits were acquired from a speaker. A total of 20,000 speech waveform files form the corpus. Recordings were performed in a quiet room. Speech was acquired at 48 kHz, with 16 bit accuracy, by means of a Digital Audio Tape-Recorder Sony TCD-D10PRO and a super-cardioid microphone Sennheiser MKH 416-T. Then, digital recordings were downsampled to 16 kHz. Speech waveform files in the corpus were stored in the NIST-SPHERE format by using the SPHERE library, version 2.6a.