Gaisah moved to the Netherlands in 2001 and currently lives and trains in Rotterdam. He competes for P.A.C. Rotterdam.
In 2005 jumped a personal best 8.34 metres to win the silver medal at the World Championships in Helsinki, finishing behind Dwight Phillips. On 2 February 2006, in Stockholm he leaped to an African indoor record that also won him the gold medal in this event by jumping 8.36 metres.[1] He continued his good form to win the 2006 IAAF World Indoor Championships a month later with a jump of 8.30 metres, followed quickly by the 2006 Commonwealth Games gold medal with a jump of 8.20 metres.
At the 2006 African Championships in Athletics Gaisah won the gold medal with an 8.51 m jump, beating Cheikh Touré's African record of 8.46 metres from 1997, but as the tail wind was too strong (+3.7 m/s) the result could not become a new record.[2]
Since July 2013 Gaisah officially competes for the Netherlands after gaining his Dutch passport.[3]