The 49-year old coach is convinced of his side's credentials after their performances in recent weeks
The 14-time league title winners are third in the table, one point behind Ajax and just three adrift of league leaders PSV.
"I don't know why Feyenoord can't be champions," Koeman told de Telegraaf.
Feyenoord recently beat the league leaders 2-1 and followed that up with a 3-0 win over NEC on Sunday, strengthening their push for honours.
Speaking after his side's victory Koeman said: "We go for the maximum, that way it makes no sense to hide.
"Last week we had to win against PSV, after PSV and Ajax won against VVV-Venlo and FC Twente, we had to win against NEC. The team delivered twice and didn't succumb to the pressure."
The Rotterdam club remain unbeaten at their De Kuip home so far this season and have nine games remaining to close the gap on PSV.