Maurice Gibb died in January 2003 at the relatively young age of 53; his fraternal twin Robin died May 2012, aged 62. Shortly after Robin's death, the BBC screened a tribute programme that included archive footage and interviews with all three brothers. Here, Maurice said this song began with him playing a melody on the piano.
Running to 3 minutes 45 seconds, "Lonely Days" was released on the Poyldor label in November 1970 backed by "Man For All Seasons", having been recorded at IBC Studios, London, the previous August. It was credited to the three brothers: Barry, Maurice and Robin.
The song was written during the same afternoon as The Bee Gees' US chart-topper "How Can You Mend A Broken Heart?" in Barry Gibb's basement flat at Addison Road, Holland Park, London.