This study investigated the perceived strategies used to deal with mixed ability classes of four English teachers, two working at a year 4-9 compulsory school, and two at an upper secondary school in Sweden. The same teachers were asked about their attitudes towards and experience of ability grouping. The findings of the latter part of this investigation were discussed in reference to research concerning the field of ability grouping.Semi structured interviews were used. Strategies used by teachers included grouping devices, issues of communication, giving individual attention inside and outside the classroom and encouraging self- and peer reviewing. Two teachers in the 4-9 school used ability grouping sparingly but clearly and had experienced an ability grouping of a year nine class which was perceived to have predominantly positive results in academic terms and both positive and negative results in social areas. The teachers of upper secondary school did not use ability grouping – either on democratic grounds or because it was perceived to be unacceptable in the particular school climate. Because the research in ability grouping is diverse, many of the teachers’ attitudes could be supported, and refuted in the research. The teachers using ability grouping felt themselves to be going against research made, but were confident in the decisions they made. Further investigations about maximum numbers of students in heterogeneous classes and time spent with an extra teacher contra own teacher were encouraged.