This is the debut of Dog, Columbo's pet basset hound.
Blythe Danner was about five months pregnant with Gwyneth Paltrow during filming. Her baby-bump is most clearly visible in the scene where she is playing tennis.
Étude in Black (1972) was originally written by Steven Bochco as a regular 90-minute episode; however, it was decided at the last minute to make it into a 120-minute episode. Producer/writer Dean Hargrove was brought in to write additional scenes to pad out the length. However, in Canada, it was aired as a regular 90-minute episode with the additional scenes cut.
Columbo's salary of $11,000.00 is equal to ~$76,000 in 2022.
Director Nicholas Colasanto would later be a familiar face on 1980s TV as barman Ernie 'Coach' Pantusso in Cheers (1982).