The ink-thrower, identified as Brijesh Shukla, was arrested.
He shouted that he was an "angry citizen of Delhi" and threw ink smearing Sisodia's face.
The Deputy Chief Minster was briefing reporters after his meeting with Lieutenant Governor Najeeb Jung.
Sisodia returned last night from his Finland tour.
The Lieutenant Governor had asked Sisodia to cut short his trip and give him a report on the dengue and chikungunya situation. in the capital.
Chief Minister Arvind Kejriwal was also away from Delhi because of a surgery he underwent in Bengaluru and returned only on Sunday.
Sisodia told reporters that he discussed with Jung the great education system in that country.
Sisodia had earlier met Mr Kejriwal.
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